Percentage points added to the reference rate to compute the variable rate on the debt instrument.

No definition available.

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage price of original principal amount of debt at which debt can be redeemed by the issuer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
-Paragraph 3
-Subparagraph e
-URI http://asc.fasb.org/extlink&oid=75038535&loc=d3e64711-112823

+ Details

Name:	us-gaap_DebtInstrumentRedemptionPricePercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of principal amount of debt redeemed.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentRedemptionPricePercentageOfPrincipalAmountRedeemed
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Weighted average interest rate of debt outstanding.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtWeightedAverageInterestRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Fair value of the amount outstanding under the credit facility.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 10
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=77997519&loc=d3e13433-108611

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=77997519&loc=d3e13476-108611

+ Details

Name:	us-gaap_LineOfCreditFacilityFairValueOfAmountOutstanding
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Including the current and noncurrent portions, carrying value as of the balance sheet date of uncollateralized debt obligations (with maturities initially due after one year or beyond the operating cycle if longer).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(16))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

+ Details

Name:	us-gaap_UnsecuredDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Secured and Unsecured Debt Financings (Details 1) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Jun. 30, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Borrowings from unsecured financings, net of debt issuance costs		$ 3,283,747	$ 3,287,211
Notes Payable, Other Payables \| ECA Term Financings {Member]
Debt Instrument [Line Items]
Debt, Weighted Average Interest Rate		3.5227%
Notes Payable, Other Payables \| Bank Financings
Debt Instrument [Line Items]
Debt, Weighted Average Interest Rate		3.4099%
Senior Notes \| Senior Notes Due 2024 [Member]
Debt Instrument [Line Items]
Interest rate		4.125%
Borrowings from unsecured financings, net of debt issuance costs		$ 500,000	0
Senior Notes \| Senior Notes Due 2020
Debt Instrument [Line Items]
Interest rate		7.625%
Borrowings from unsecured financings, net of debt issuance costs		$ 300,000	300,000
Senior Notes \| Senior Notes due 2021
Debt Instrument [Line Items]
Interest rate		5.125%
Borrowings from unsecured financings, net of debt issuance costs		$ 500,000	500,000
Senior Notes \| Senior Notes Due 2022 [Member]
Debt Instrument [Line Items]
Interest rate		5.50%
Borrowings from unsecured financings, net of debt issuance costs		$ 500,000	500,000
Line of Credit \| Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Borrowings from unsecured financings, net of debt issuance costs			$ 0
Line of Credit \| 2013 Revolving Credit Facility \| Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Fair Value of Amount Outstanding		$ 0
Senior Notes Due 2024 [Member] \| Senior Notes Due 2024 [Member]
Debt Instrument [Line Items]
Interest rate	4.125%
Borrowings from unsecured financings, net of debt issuance costs	$ 500,000
Debt Instrument, Redemption, Period One [Member] \| Senior Notes Due 2024 [Member] \| Senior Notes Due 2024 [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.50%
Debt Instrument, Redemption Price, Percentage	104.125%
Debt Instrument, Redemption, Period Two [Member] \| Senior Notes Due 2024 [Member] \| Senior Notes Due 2024 [Member]
Debt Instrument [Line Items]
Debt Instrument, Redemption Price, Percentage	101.00%
Maximum \| Notes Payable, Other Payables \| ECA Term Financings {Member]
Debt Instrument [Line Items]
Interest rate		3.96%
Maximum \| Notes Payable to Banks \| Bank Financings
Debt Instrument [Line Items]
Interest rate		4.45%
Maximum \| Debt Instrument, Redemption, Period One [Member] \| Senior Notes Due 2024 [Member] \| Senior Notes Due 2024 [Member]
Debt Instrument [Line Items]
Debt Instrument, Redemption Price, Percentage of Principal Amount Redeemed	100.00%
Maximum \| Debt Instrument, Redemption, Period Two [Member] \| Senior Notes Due 2024 [Member] \| Senior Notes Due 2024 [Member]
Debt Instrument [Line Items]
Debt Instrument, Redemption Price, Percentage of Principal Amount Redeemed	40.00%