Summary of Significant Accounting Policies (Details 4) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Domestic Leveraged Lease [Member]
Net Investments from Leveraged Lease
Net rentals receivable	$ 482	$ 475
Unearned income	(205)	(207)
Investment in leveraged leases	277	268
Deferred taxes from leveraged leases	(238)	(223)
Net investment in leveraged leases	39	45
Components of Income from Leveraged Lease
Pretax leveraged lease income	10	4	12
Income tax expense	(4)	(3)	(5)
Net leveraged lease income	6	1	7
International Leverage Lease [Member]
Net Investments from Leveraged Lease
Net rentals receivable	734	733
Unearned income	(362)	(377)
Investment in leveraged leases	372	356
Deferred taxes from leveraged leases	(39)	(40)
Net investment in leveraged leases	333	316
Components of Income from Leveraged Lease
Pretax leveraged lease income	15	14	19
Income tax expense	(5)	(5)	(7)
Net leveraged lease income	$ 10	$ 9	$ 12