v3.7.0.1
Debt and Capital Leases (Details 1 - Debt Table) - USD ($)
$ in Millions
3 Months Ended
Mar. 31, 2017
Dec. 31, 2016
Debt and Capital Leases    
Long-term Debt $ 19,465 $ 19,324
Capital Lease Obligations 12 8
Subtotal 19,477 19,332
Less current maturities (1,688) (1,220)
Deferred Finance Costs, Net (191) (188)
Debt Instrument, Unamortized Discount (Premium), Net 74 82
Total long-term debt and capital leases $ 17,672 18,006
Interest rate, variable basis 3 month LIBOR  
Recourse Debt [Member]    
Debt and Capital Leases    
Long-term Debt $ 7,915 7,795
Non Recourse Debt [Member]    
Debt and Capital Leases    
Long-term Debt 11,550 11,529
Senior Notes Due In 2018 [Member] | Recourse Debt [Member]    
Debt and Capital Leases    
Long-term Debt $ 398 398
Debt Instrument, Interest Rate, Stated Percentage [1] 7.625%  
Senior Notes Due In 2021 [Member] | Recourse Debt [Member]    
Debt and Capital Leases    
Long-term Debt $ 207 207
Debt Instrument, Interest Rate, Stated Percentage [1] 7.875%  
Senior Notes Due In 2022 [Member] | Recourse Debt [Member]    
Debt and Capital Leases    
Long-term Debt $ 992 992
Debt Instrument, Interest Rate, Stated Percentage [1] 6.25%  
Senior Notes Due in 2023 [Member] | Recourse Debt [Member]    
Debt and Capital Leases    
Long-term Debt $ 869 869
Debt Instrument, Interest Rate, Stated Percentage [1] 6.625%  
Senior Notes 2024 [Member] | Recourse Debt [Member]    
Debt and Capital Leases    
Long-term Debt $ 733 733
Debt Instrument, Interest Rate, Stated Percentage [1] 6.25%  
Senior Notes due 2026 [Member] | Recourse Debt [Member]    
Debt and Capital Leases    
Long-term Debt $ 1,000 1,000
Debt Instrument, Interest Rate, Stated Percentage [1] 7.25%  
Senior Notes due 2027 [Member] | Recourse Debt [Member]    
Debt and Capital Leases    
Long-term Debt $ 1,250 1,250
Debt Instrument, Interest Rate, Stated Percentage [1] 6.625%  
Term Loan Facility Due 2023 [Member]    
Debt and Capital Leases    
Interest rate, variable basis 1 - month LIBOR  
Term Loan Facility Due 2023 [Member] | Recourse Debt [Member]    
Debt and Capital Leases    
Long-term Debt $ 1,886 1,891
Revolving Credit Facility [Member]    
Debt and Capital Leases    
Interest rate, variable basis 1 - month LIBOR  
Revolving Credit Facility [Member] | Recourse Debt [Member]    
Debt and Capital Leases    
Long-term Debt $ 125 0
Tax-exempt Bonds [Member] | Recourse Debt [Member]    
Debt and Capital Leases    
Long-term Debt 455 455
GenOn Senior Notes [Member] | Non Recourse Debt [Member]    
Debt and Capital Leases    
Long-term Debt $ 1,830 1,830
GenOn Senior Notes Due in 2017 [Member] | Non Recourse Debt [Member]    
Debt and Capital Leases    
Debt Instrument, Interest Rate, Stated Percentage [1] 7.875%  
GenOn senior notes, due 2018 | Non Recourse Debt [Member]    
Debt and Capital Leases    
Debt Instrument, Interest Rate, Stated Percentage [1] 9.50%  
GenOn senior notes, due 2020 | Non Recourse Debt [Member]    
Debt and Capital Leases    
Debt Instrument, Interest Rate, Stated Percentage [1] 9.875%  
GenOn Americas Generation Senior Notes [Member] | Non Recourse Debt [Member]    
Debt and Capital Leases    
Long-term Debt $ 695 695
GenOn Americas Generation Senior Notes Due in 2021 [Member] | Non Recourse Debt [Member]    
Debt and Capital Leases    
Debt Instrument, Interest Rate, Stated Percentage [1] 8.50%  
GenOn Americas Generation senior notes, due in 2031 | Non Recourse Debt [Member]    
Debt and Capital Leases    
Debt Instrument, Interest Rate, Stated Percentage [1] 9.125%  
GenOn Other [Member] | Non Recourse Debt [Member]    
Debt and Capital Leases    
Long-term Debt $ 95 96
Genon [Member] | Non Recourse Debt [Member]    
Debt and Capital Leases    
Long-term Debt 2,620 2,621
5.375% Senior Notes due in 2024 [Member] | Non Recourse Debt [Member]    
Debt and Capital Leases    
Long-term Debt $ 500 500
Debt Instrument, Interest Rate, Stated Percentage [1] 5.375%  
5.00% Senior Notes due in 2026 [Member] | Non Recourse Debt [Member]    
Debt and Capital Leases    
Long-term Debt $ 350 350
Debt Instrument, Interest Rate, Stated Percentage [1] 5.00%  
3.5% Convertible Notes due 2019 [Member] | Non Recourse Debt [Member]    
Debt and Capital Leases    
Long-term Debt $ 345 345
Debt Instrument, Interest Rate, Stated Percentage [1] 3.50%  
3.25% Convertible Notes due 2020 [Member] | Non Recourse Debt [Member]    
Debt and Capital Leases    
Long-term Debt $ 288 288
Debt Instrument, Interest Rate, Stated Percentage [1] 3.25%  
West Holdings Credit Agreement [Member] | Non Recourse Debt [Member]    
Debt and Capital Leases    
Long-term Debt $ 414 443
Marsh Landing Term Loan Facility [Member]    
Debt and Capital Leases    
Interest rate, variable basis 1 - month LIBOR  
Marsh Landing Term Loan Facility [Member] | Non Recourse Debt [Member]    
Debt and Capital Leases    
Long-term Debt $ 361 370
Alta Wind I - V Lease financing arrangement [Member] | Non Recourse Debt [Member]    
Debt and Capital Leases    
Long-term Debt $ 965 965
Alta Wind I [Member] | Non Recourse Debt [Member]    
Debt and Capital Leases    
Debt Instrument, Interest Rate, Stated Percentage [1] 7.015%  
Alta Wind II [Member] | Non Recourse Debt [Member]    
Debt and Capital Leases    
Debt Instrument, Interest Rate, Stated Percentage [1] 5.696%  
Alta Wind III [Member] | Non Recourse Debt [Member]    
Debt and Capital Leases    
Debt Instrument, Interest Rate, Stated Percentage [1] 6.067%  
Alta Wind IV [Member] | Non Recourse Debt [Member]    
Debt and Capital Leases    
Debt Instrument, Interest Rate, Stated Percentage [1] 5.938%  
Alta Wind V [Member] | Non Recourse Debt [Member]    
Debt and Capital Leases    
Debt Instrument, Interest Rate, Stated Percentage [1] 6.071%  
Walnut Creek Energy, LLC, due in 2023 [Member]    
Debt and Capital Leases    
Interest rate, variable basis 1 - month LIBOR  
Walnut Creek Energy, LLC, due in 2023 [Member] | Non Recourse Debt [Member]    
Debt and Capital Leases    
Long-term Debt $ 303 310
Interest rate, variable basis [1] LIBOR  
Utah Portfolio [Member]    
Debt and Capital Leases    
Interest rate, variable basis 1 - month LIBOR  
Utah Portfolio [Member] | Non Recourse Debt [Member]    
Debt and Capital Leases    
Long-term Debt $ 287 287
Tapestry Wind LLC due in 2021 [Member] | Non Recourse Debt [Member]    
Debt and Capital Leases    
Long-term Debt $ 168 172
Interest rate, variable basis [1] LIBOR  
CVSR due 2037 [Member] | Non Recourse Debt [Member]    
Debt and Capital Leases    
Long-term Debt $ 757 771
CVSR Holdco due 2037 [Member] | Non Recourse Debt [Member]    
Debt and Capital Leases    
Long-term Debt $ 194 199
Debt Instrument, Interest Rate, Stated Percentage [1] 4.68%  
NRG Solar Alpine LLC, due 2022    
Debt and Capital Leases    
Interest rate, variable basis 1 - month LIBOR  
NRG Solar Alpine LLC, due 2022 | Non Recourse Debt [Member]    
Debt and Capital Leases    
Long-term Debt $ 144 145
NRG Energy Center Minneapolis LLC, senior secured notes, due 2013, 2017, and 2025 | Non Recourse Debt [Member]    
Debt and Capital Leases    
Long-term Debt $ 94 96
NRG Energy Center Minneapolis LLC Senior Secured Notes, due 2025 | Non Recourse Debt [Member]    
Debt and Capital Leases    
Debt Instrument, Interest Rate, Stated Percentage [1] 5.95%  
NRG Energy Center Minneapolis LLC Senior Secured Notes due 2031 [Member] | Non Recourse Debt [Member]    
Debt and Capital Leases    
Long-term Debt $ 125 125
Debt Instrument, Interest Rate, Stated Percentage [1] 3.55%  
Viento Funding II, Inc., due in 2023 [Member]    
Debt and Capital Leases    
Interest rate, variable basis 1 - month LIBOR  
Viento Funding II, Inc., due in 2023 [Member] | Non Recourse Debt [Member]    
Debt and Capital Leases    
Long-term Debt $ 178 178
Interest rate, variable basis [1] LIBOR  
NRG Yield - Other [Member] | Non Recourse Debt [Member]    
Debt and Capital Leases    
Long-term Debt $ 578 540
NRG Yield, Inc. | Non Recourse Debt [Member]    
Debt and Capital Leases    
Long-term Debt 6,051 6,084
Ivanpah Financing, due 2014 and 2038 | Non Recourse Debt [Member]    
Debt and Capital Leases    
Long-term Debt 1,108 1,113
Agua Caliente Solar LLC, due 2037 | Non Recourse Debt [Member]    
Debt and Capital Leases    
Long-term Debt 846 849
Agua Caliente Holdco, due 2038 [Member] | Non Recourse Debt [Member]    
Debt and Capital Leases    
Long-term Debt $ 89 0
Debt Instrument, Interest Rate, Stated Percentage [1] 5.43%  
Cedro Hill Wind LLC, due in 2025 [Member] | Non Recourse Debt [Member]    
Debt and Capital Leases    
Long-term Debt $ 161 163
Interest rate, variable basis [1] LIBOR  
Midwest Generation due 2019 [Member] | Non Recourse Debt [Member]    
Debt and Capital Leases    
Long-term Debt $ 213 231
Debt Instrument, Interest Rate, Stated Percentage [1] 4.39%  
Other (Non-recourse debt) | Non Recourse Debt [Member]    
Debt and Capital Leases    
Long-term Debt $ 462 468
NRG Energy [Member] | Non Recourse Debt [Member]    
Debt and Capital Leases    
Long-term Debt 2,879 $ 2,824
Senior Notes [Member] | Recourse Debt [Member]    
Debt and Capital Leases    
Long-term Debt $ 5,400  
London Interbank Offered Rate (LIBOR) [Member] | Term Loan Facility Due 2023 [Member] | Recourse Debt [Member]    
Debt and Capital Leases    
Interest rate, variable basis [1] LIBOR  
Interest rate, basis spread on variable rate [1] 2.25%  
London Interbank Offered Rate (LIBOR) [Member] | Revolving Credit Facility [Member] | Recourse Debt [Member]    
Debt and Capital Leases    
Interest rate, variable basis [1] LIBOR  
Interest rate, basis spread on variable rate [1] 2.25%  
London Interbank Offered Rate (LIBOR) [Member] | West Holdings Credit Agreement [Member] | Non Recourse Debt [Member]    
Debt and Capital Leases    
Interest rate, variable basis [1] LIBOR  
London Interbank Offered Rate (LIBOR) [Member] | Marsh Landing Term Loan Due 2017 [Member] | Non Recourse Debt [Member]    
Debt and Capital Leases    
Interest rate, variable basis [1] LIBOR  
Interest rate, basis spread on variable rate [1] 1.75%  
London Interbank Offered Rate (LIBOR) [Member] | GenOn Marsh Landing term loan, due 2023 | Non Recourse Debt [Member]    
Debt and Capital Leases    
Interest rate, variable basis [1] LIBOR  
Interest rate, basis spread on variable rate [1] 1.875%  
London Interbank Offered Rate (LIBOR) [Member] | Walnut Creek Energy, LLC, due in 2023 [Member] | Non Recourse Debt [Member]    
Debt and Capital Leases    
Interest rate, basis spread on variable rate [1] 1.625%  
London Interbank Offered Rate (LIBOR) [Member] | Utah Portfolio [Member] | Non Recourse Debt [Member]    
Debt and Capital Leases    
Interest rate, variable basis [1] LIBOR  
Interest rate, basis spread on variable rate [1] 2.65%  
London Interbank Offered Rate (LIBOR) [Member] | Tapestry Wind LLC due in 2021 [Member] | Non Recourse Debt [Member]    
Debt and Capital Leases    
Interest rate, basis spread on variable rate [1] 1.625%  
London Interbank Offered Rate (LIBOR) [Member] | NRG Solar Alpine LLC, due 2022 | Non Recourse Debt [Member]    
Debt and Capital Leases    
Interest rate, variable basis [1] LIBOR  
Interest rate, basis spread on variable rate [1] 1.75%  
London Interbank Offered Rate (LIBOR) [Member] | Viento Funding II, Inc., due in 2023 [Member] | Non Recourse Debt [Member]    
Debt and Capital Leases    
Interest rate, basis spread on variable rate [1] 2.75%  
London Interbank Offered Rate (LIBOR) [Member] | Cedro Hill Wind LLC, due in 2025 [Member] | Non Recourse Debt [Member]    
Debt and Capital Leases    
Interest rate, basis spread on variable rate [1] 1.75%  
Minimum [Member] | Fort Bend County, tax-exempt bonds, due 2038 and 2042 | Recourse Debt [Member]    
Debt and Capital Leases    
Debt Instrument, Interest Rate, Stated Percentage [1] 4.125%  
Minimum [Member] | CVSR due 2037 [Member] | Non Recourse Debt [Member]    
Debt and Capital Leases    
Debt Instrument, Interest Rate, Stated Percentage [1] 2.339%  
Minimum [Member] | NRG Energy Center Minneapolis LLC Senior Secured Notes, due 2017 | Non Recourse Debt [Member]    
Debt and Capital Leases    
Debt Instrument, Interest Rate, Stated Percentage [1] 7.12%  
Minimum [Member] | Ivanpah Financing, due 2014 and 2038 | Non Recourse Debt [Member]    
Debt and Capital Leases    
Debt Instrument, Interest Rate, Stated Percentage [1] 2.285%  
Minimum [Member] | Agua Caliente Solar LLC, due 2037 | Non Recourse Debt [Member]    
Debt and Capital Leases    
Debt Instrument, Interest Rate, Stated Percentage [1] 2.395%  
Minimum [Member] | London Interbank Offered Rate (LIBOR) [Member] | West Holdings Credit Agreement [Member] | Non Recourse Debt [Member]    
Debt and Capital Leases    
Debt Instrument, Interest Rate, Stated Percentage [1] 1.625%  
Maximum [Member] | Fort Bend County, tax-exempt bonds, due 2038 and 2042 | Recourse Debt [Member]    
Debt and Capital Leases    
Debt Instrument, Interest Rate, Stated Percentage [1] 6.00%  
Maximum [Member] | CVSR due 2037 [Member] | Non Recourse Debt [Member]    
Debt and Capital Leases    
Debt Instrument, Interest Rate, Stated Percentage [1] 3.775%  
Maximum [Member] | NRG Energy Center Minneapolis LLC Senior Secured Notes, due 2017 | Non Recourse Debt [Member]    
Debt and Capital Leases    
Debt Instrument, Interest Rate, Stated Percentage [1] 7.25%  
Maximum [Member] | Ivanpah Financing, due 2014 and 2038 | Non Recourse Debt [Member]    
Debt and Capital Leases    
Debt Instrument, Interest Rate, Stated Percentage [1] 4.256%  
Maximum [Member] | Agua Caliente Solar LLC, due 2037 | Non Recourse Debt [Member]    
Debt and Capital Leases    
Debt Instrument, Interest Rate, Stated Percentage [1] 3.633%  
Maximum [Member] | London Interbank Offered Rate (LIBOR) [Member] | West Holdings Credit Agreement [Member] | Non Recourse Debt [Member]    
Debt and Capital Leases    
Debt Instrument, Interest Rate, Stated Percentage [1] 2.25%  
[1] As of March 31, 2017, L+ equals 3 month LIBOR plus x%, with the exception of the Viento Funding II term loan, the Utah Portfolio term loans, the Alpine Term Loan, the NRG Marsh Landing term loan, the Walnut Creek term loan, the 2023 Term Loan Facility, and the Revolving credit facility which are 1 month LIBOR plus x%.