Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Statement of Cash Flows [Abstract]
Net income	$ 29,781	$ 32,868	$ 124,270
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	284,924	269,920	242,103
Amortization of deferred financing costs	14,719	12,449	15,271
Amortization of net lease discounts and lease incentives	32,411	12,844	16,445
Deferred income taxes	4,416	6,828	5,615
Non-cash share based payment expense	4,569	4,232	5,786
Net derivative loss reclassified into earnings	33,265	30,777	23,078
Ineffective portion of cash flow hedges	371	2,893	(101)
Security deposits and maintenance payments included in earnings	(60,112)	(54,180)	(35,500)
Gain on the sale of flight equipment	(37,220)	(5,747)	(39,092)
Impairment of aircraft	117,306	96,454	6,436
Earnings of unconsolidated equity method investment, net of tax	(53)	0	0
Other	(5,641)	(2,218)	742
Changes on certain assets and liabilities:
Accounts receivable	3,397	(2,530)	(4,818)
Restricted cash and cash equivalents related to operating activities	0	0	4,418
Other assets	1,164	919	(2,675)
Accounts payable, accrued expenses and other liabilities	3,016	17,732	(1,848)
Lease rentals received in advance	(2,276)	4,036	(753)
Net cash provided by operating activities	424,037	427,277	359,377
Cash flows from investing activities:
Acquisition and improvement of flight equipment	(1,263,706)	(693,227)	(776,750)
Proceeds from sale of flight equipment	568,045	61,489	489,196
Restricted cash and cash equivalents related to sale of flight equipment	0	35,762	(35,762)
Aircraft purchase deposits and progress payments, net of returned deposits and aircraft sales deposits	(6,094)	(20,553)	(122,069)
Net investment in finance leases	(11,595)	(91,500)	0
Collections on finance leases	9,508	3,852	0
Unconsolidated equity method investment and associated costs	(20,189)	0	0
Purchase of debt investment	0	(43,626)	0
Principal repayments on debt investment	42,001	6,585	0
Other	(903)	(691)	(35)
Net cash used in investing activities	(682,933)	(741,909)	(445,420)
Cash flows from financing activities:
Issuance of shares net of repurchases	197,437	(44,180)	(91,610)
Proceeds from notes and term debt financings	563,230	1,459,690	669,047
Securitization and term debt financing repayments	(510,162)	(847,415)	(390,945)
Deferred financing costs	(10,865)	(31,691)	(20,179)
Restricted secured liquidity facility collateral	0	(3,000)	35,000
Secured liquidity facility collateral	0	(3,000)	35,000
Restricted cash and cash equivalents related to security deposits and maintenance payments	(10,831)	99,748	(25,056)
Security deposits received	20,889	17,453	20,574
Security deposits returned	(5,104)	(6,152)	(7,914)
Maintenance payments received	179,789	142,122	122,050
Maintenance payments returned	(77,033)	(57,822)	(89,300)
Payments for terminated cash flow hedges and payment for option	0	(50,757)	0
Dividends paid	(52,058)	(43,669)	(45,059)
Net cash provided by financing activities	295,292	637,327	141,608
Net increase in cash and cash equivalents	36,396	322,695	55,565
Cash and cash equivalents at beginning of year	618,217	295,522	239,957
Cash and cash equivalents at end of year	654,613	618,217	295,522
Supplemental disclosures of cash flow information:
Cash paid during the year for interest, net of capitalized interest	195,350	167,069	162,938
Cash paid during the year for income taxes	487	2,468	2,054
Supplemental disclosures of non-cash investing activities:
Security deposits, maintenance liabilities and other liabilities settled in sale of flight equipment	58,862	4,135	21,585
Advance lease rentals, security deposits and maintenance reserves assumed in asset acquisitions	88,882	24,261	5,666
Term debt financings assumed in asset acquisitions	$ 84,721	$ 0	$ 0