Equipment Under Operating Leases, Net of Accumulated Depreciation - Equipment Under Operating Leases (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Property Subject to or Available for Operating Lease [Line Items]
Total of Equipment under operating leases, net of accumulated depreciation	$ 1,358	$ 1,439
Equipment [Member]
Property Subject to or Available for Operating Lease [Line Items]
Cost	2,146	2,364
Advanced rent receipts, net	(38)	(42)
Accumulated depreciation	(750)	(883)
Total of Equipment under operating leases, net of accumulated depreciation	$ 1,358	$ 1,439