Loans Held for Investment portfolio and Related Allowance for Loan and Lease Losses (Detail) (USD $) In Millions, unless otherwise specified	Mar. 31, 2012		Dec. 31, 2011		Mar. 31, 2011	Dec. 31, 2010
Individually evaluated	$ 3,411		$ 3,592
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	400		448
Collectively evaluated	118,867		118,470
Total evaluated	122,278		122,062
Loans carried at fair value	413		433
Total	122,691	[1]	122,495	[1]
Individually evaluated	400		448
Collectively evaluated	1,948		2,009
Total evaluated	2,348		2,457
Total LHFI	2,348		2,457		2,854	2,974
Commercial Portfolio Segment
Individually evaluated	321		412
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	16		34
Collectively evaluated	55,862		55,458
Total evaluated	56,183		55,870
Loans carried at fair value	2		2
Total	56,185		55,872
Individually evaluated	16		34
Collectively evaluated	885		930
Total evaluated	901		964
Total LHFI	901		964		1,255	1,303
Residential Mortgage Loans
Individually evaluated	3,052		3,141
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	376		405
Collectively evaluated	43,033		43,088
Total evaluated	46,085		46,229
Loans carried at fair value	411		431
Total	46,496		46,660
Individually evaluated	376		405
Collectively evaluated	939		949
Total evaluated	1,315		1,354
Total LHFI	1,315		1,354		1,440	1,498
Consumer Portfolio Segment
Individually evaluated	38		39
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	8		9
Collectively evaluated	19,972		19,924
Total evaluated	20,010		19,963
Loans carried at fair value	0		0
Total	20,010		19,963
Individually evaluated	8		9
Collectively evaluated	124		130
Total evaluated	132		139
Total LHFI	$ 132		$ 139		$ 159	$ 173

[1] Includes loans of consolidated VIEs1,378 3,322