Loans Held for Investment portfolio and Related Allowance for Loan and Lease Losses (Detail) (USD $) In Millions, unless otherwise specified	Mar. 31, 2014		Dec. 31, 2013		Mar. 31, 2013	Dec. 31, 2012
Individually evaluated	$ 3,100		$ 3,159
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	380		363
Collectively evaluated	125,797		124,416
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	1,660		1,681
Total evaluated	128,897		127,575
Loans And Leases Receivable Allowance Loans Evaluated For Impairment Excluding Fair Value Loans	2,040		2,044
Loans Receivable, Fair Value Disclosure	299		302
Total	129,196	[1]	127,877	[1]
Loans and Leases Receivable, Allowance	2,040		2,044		2,152	2,174
Commercial Portfolio Segment [Member]
Individually evaluated	141		171
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	15		10
Collectively evaluated	65,568		64,139
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	951		936
Total evaluated	65,709		64,310
Loans And Leases Receivable Allowance Loans Evaluated For Impairment Excluding Fair Value Loans	966		946
Loans Receivable, Fair Value Disclosure	0		0
Total	65,709		64,310
Loans and Leases Receivable, Allowance	966		946		921	902
Residential Portfolio Segment [Member]
Individually evaluated	2,843		2,878
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	357		345
Collectively evaluated	39,653		40,010
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	553		585
Total evaluated	42,496		42,888
Loans And Leases Receivable Allowance Loans Evaluated For Impairment Excluding Fair Value Loans	910		930
Loans Receivable, Fair Value Disclosure	299		302
Total	42,795		43,190
Loans and Leases Receivable, Allowance	910		930		1,087	1,131
Consumer Portfolio Segment [Member]
Individually evaluated	116		110
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	8		8
Collectively evaluated	20,576		20,267
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	156		160
Total evaluated	20,692		20,377
Loans And Leases Receivable Allowance Loans Evaluated For Impairment Excluding Fair Value Loans	164		168
Loans Receivable, Fair Value Disclosure	0		0
Total	20,692		20,377
Loans and Leases Receivable, Allowance	$ 164		$ 168		$ 144	$ 141

[1] Includes loans of consolidated VIEs of $318 million and $327 million at March 31, 2014 and December 31, 2013, respectively.