Debt Financing (Details) (USD $)							0 Months Ended				0 Months Ended	6 Months Ended	0 Months Ended	3 Months Ended	6 Months Ended		3 Months Ended			0 Months Ended									0 Months Ended	6 Months Ended
	Jun. 30, 2013	Dec. 31, 2012	Jun. 30, 2013 Unsecured	Dec. 31, 2012 Unsecured	Jun. 30, 2013 Senior notes	Dec. 31, 2012 Senior notes	Feb. 05, 2013 4.75% senior unsecured notes due 2020	Feb. 05, 2013 4.75% senior unsecured notes due 2020 Minimum item	Jun. 30, 2013 Revolving credit facilities	Dec. 31, 2012 Revolving credit facilities	May 07, 2013 Syndicated Unsecured Revolving Credit Facility	Jun. 30, 2013 Syndicated Unsecured Revolving Credit Facility	May 07, 2013 Syndicated Unsecured Revolving Credit Facility Amendment and restatement of syndicated unsecured revolving credit agreement	Jun. 30, 2013 Unsecured term financings item	Jun. 30, 2013 Unsecured term financings item	Dec. 31, 2012 Unsecured term financings	Jun. 30, 2013 Unsecured term financings Minimum	Jun. 30, 2013 Unsecured term financings Maximum	Jun. 26, 2013 7.375% senior unsecured notes due January 30, 2019	Jun. 26, 2013 5.625% senior notes due 2017	Jun. 26, 2013 5.625% senior notes due 2017 Minimum item	Jun. 26, 2013 5.625% senior notes due 2017 Maximum	Jun. 30, 2013 Convertible senior notes	Dec. 31, 2012 Convertible senior notes	Jun. 30, 2013 Secured item	Dec. 31, 2012 Secured item	Jun. 30, 2013 Warehouse facilities item	Dec. 31, 2012 Warehouse facilities item	Jun. 21, 2013 2010 Warehouse Facility	Jun. 30, 2013 2010 Warehouse Facility	Jun. 21, 2013 Amended 2010 Warehouse Facility	Jun. 30, 2013 Secured term financings	Dec. 31, 2012 Secured term financings	Jun. 30, 2013 Export credit financing
Debt financing
Secured and unsecured debt financing	$ 5,239,021,000	$ 4,394,355,000	$ 3,606,049,000	$ 2,643,916,000	$ 2,170,620,000	$ 1,775,000,000			$ 950,000,000	$ 420,000,000				$ 285,429,000	$ 285,429,000	$ 248,916,000							$ 200,000,000	$ 200,000,000	$ 1,632,972,000	$ 1,750,439,000	$ 842,133,000	$ 1,061,838,000				$ 715,973,000	$ 688,601,000	$ 74,866,000
Less: Debt discount	(12,679,000)	(9,623,000)
Total debt	5,226,342,000	4,384,732,000
Secured Obligations
Nonrecourse																									863,842,000	1,085,941,000
Recourse																									769,130,000	664,498,000
Total																									1,632,972,000	1,750,439,000
Number of aircraft pledged as collateral																									52	55	32	38
Net book value of aircraft pledged as collateral																									2,504,910,000	2,728,636,000	1,300,000,000	1,600,000,000
Aggregate principal amount of debt offered to exchange of existing debt																			125,400,000			151,600,000
Increase in borrowings							400,000,000							120,500,000						132,000,000
Interest rate (as a percent)							4.75%												7.375%	5.625%
Additional interest rate (as a percent)							0.50%													0.50%
Number of rating agencies by whom publicly available rating on notes should be maintained								1													1
Capacity provided													1,700,000,000																1,250,000,000		1,000,000,000
Variable interest rate floor (as a percent)												0.00%	0.00%
Term of debt											3 years		4 years				2 years	5 years											4 years	4 years
Number of additional term facilities bearing fixed interest rate															3
Fixed interest rate (as a percent)																	3.00%	3.10%
Variable interest basis												LIBOR	LIBOR	LIBOR															LIBOR
Interest margin (as a percent)												1.75%	1.45%	1.45%	1.45%														2.50%		2.25%
Interest rate on undrawn balances (as a percent)																													0.75%		0.50%
Commitment fee in respect of unutilized commitments (as a percent)												0.375%	0.30%
Increase in aggregate principal amount of facility													607,000,000
Amount outstanding									950,000,000																		842,100,000	1,100,000,000		664,300,000
Number of additional term facilities														4
Cash collateral and lessee deposits pledged																											70,500,000	104,300,000
Maturities
2013	98,350,000
2014	229,848,000
2015	250,298,000
2016	897,974,000
2017	2,384,228,000
Thereafter	1,378,323,000
Total	$ 5,239,021,000	$ 4,394,355,000	$ 3,606,049,000	$ 2,643,916,000	$ 2,170,620,000	$ 1,775,000,000			$ 950,000,000	$ 420,000,000				$ 285,429,000	$ 285,429,000	$ 248,916,000							$ 200,000,000	$ 200,000,000	$ 1,632,972,000	$ 1,750,439,000	$ 842,133,000	$ 1,061,838,000				$ 715,973,000	$ 688,601,000	$ 74,866,000