The amortization period of the difference between the amount at which an investment accounted for under the equity method of accounting is carried (reported) on the balance sheet and amount of underlying equity in net assets the reporting Entity has in the investee.

No definition available.

Acquisitions (Details) $ / shares in Units, $ in Thousands								3 Months Ended		9 Months Ended		12 Months Ended
Acquisitions (Details) $ / shares in Units, $ in Thousands	Nov. 02, 2016 shares	Oct. 31, 2016 shares	Jul. 21, 2016 shares	Jul. 01, 2016 USD ($)	May 06, 2016 USD ($)	Mar. 29, 2016 USD ($)	Jan. 01, 2016 USD ($) $ / shares shares	Sep. 30, 2016 USD ($)	Sep. 30, 2015 USD ($)	Sep. 30, 2016 USD ($)	Sep. 30, 2015 USD ($)	Dec. 31, 2015 USD ($)	Dec. 16, 2015 mi	Mar. 01, 2015
Business Acquisition [Line Items]
Unconsolidated investment								$ 455,401		$ 455,401		$ 0
Equity in earnings of unconsolidated investment								12,066	$ 0	35,387	$ 0
Payments to Acquire Equity Method Investments										35,452	0
Distributions to noncontrolling interests										177,449	0
Equity impact of partial exercise of call option										25,858
Derivative Asset, Noncurrent							$ 46,000
Partners' Capital Account, Units, Treasury Units Purchased \| shares			3,563,146
Acquisition of Pony Express membership interest										49,118	700,000
Water Solutions
Business Acquisition [Line Items]
Business Acquisition, Percentage of Voting Interests Acquired				8.00%
Distributions to noncontrolling interests				$ 6,000
Subsidiary of Limited Liability Company or Limited Partnership, Ownership Interest				100.00%
Rockies Express Pipeline LLC \| Rockies Express Holdings, LLC
Business Acquisition [Line Items]
Payments to Acquire Businesses, Gross						$ 440,000
Rockies Express Pipeline LLC \| Tallgrass Energy Partners
Business Acquisition [Line Items]
Payments to Acquire Businesses, Gross					$ 436,000
Pony Express Pipeline
Business Acquisition [Line Items]
Business Acquisition, Percentage of Voting Interests Acquired							31.30%							33.30%
Distributions to noncontrolling interests							$ 475,000			425,882	0
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares \| shares							6,518,000
Common unit, issuance value							$ 268,600
Total consideration							$ 743,600
Subsidiary of Limited Liability Company or Limited Partnership, Ownership Interest							98.00%
Acquisition of Pony Express membership interest										49,100
Pony Express Pipeline \| Equity Option
Business Acquisition [Line Items]
Derivative, Term of Contract							18 months
Option Indexed to Issuer's Equity, Strike Price \| $ / shares							$ 42.50
BNN Western, LLC
Business Acquisition [Line Items]
Business Acquisition, Percentage of Voting Interests Acquired													100.00%
Acquisitions												$ (75,000)
Miles of water pipeline \| mi													62
BNN Western, LLC \| Fresh Water Service Contract
Business Acquisition [Line Items]
Lessor Leasing Arrangements, Operating Leases, Term of Contract												5 years
BNN Western, LLC \| Gathering and Disposal Contract
Business Acquisition [Line Items]
Lessor Leasing Arrangements, Operating Leases, Term of Contract												9 years
Sempra U.S. Gas and Power \| Rockies Express Holdings, LLC
Business Acquisition [Line Items]
Business Acquisition, Percentage of Voting Interests Acquired					25.00%
Rockies Express Pipeline LLC
Business Acquisition [Line Items]
Equity Method Investment, Difference Between Carrying Amount and Underlying Equity								$ (399,109)		(399,109)
Basis Difference, Amortization Period					35 years
Public Utilities, Property, Plant and Equipment, Disclosure of Composite Depreciation Rate for Plants in Service					2.86%
Cash Dividends Paid to Parent Company by Unconsolidated Subsidiaries										51,500
Payments to Acquire Equity Method Investments										$ 436,022	$ 0
Rockies Express Pipeline LLC \| Tallgrass Energy Partners
Business Acquisition [Line Items]
Unconsolidated investment					$ 436,000
Equity Method Investment, Underlying Equity in Net Assets					840,700
Equity Method Investment, Difference Between Carrying Amount and Underlying Equity					$ (404,700)
Subsequent Event
Business Acquisition [Line Items]
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares \| shares	1,703,094
Partners' Capital Account, Units, Treasury Units Purchased \| shares		1,251,760