Assets and Liabilities Measured at Fair Value on a Recurring Basis (Parenthetical) (Detail) (USD $) In Millions, unless otherwise specified					3 Months Ended		9 Months Ended								3 Months Ended		9 Months Ended		3 Months Ended	9 Months Ended	12 Months Ended	3 Months Ended		9 Months Ended
	Sep. 30, 2014		Dec. 31, 2013		Sep. 30, 2014 Interest Rate Lock Commitments [Member]	Sep. 30, 2013 Interest Rate Lock Commitments [Member]	Sep. 30, 2014 Interest Rate Lock Commitments [Member]	Sep. 30, 2013 Interest Rate Lock Commitments [Member]	Sep. 30, 2014 Equity Funds [Member] Fair Value, Inputs, Level 1 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2013 Equity Funds [Member] Fair Value, Inputs, Level 1 [Member] Fair Value, Measurements, Recurring [Member]	Sep. 30, 2014 Federal Reserve Bank Stock [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2013 Federal Reserve Bank Stock [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Sep. 30, 2014 Investment in Federal Home Loan Bank Stock [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2013 Investment in Federal Home Loan Bank Stock [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Sep. 30, 2014 Collateralized Loan Obligations [Member] Fair Value, Inputs, Level 2 [Member]	Sep. 30, 2013 Collateralized Loan Obligations [Member] Fair Value, Inputs, Level 2 [Member]	Sep. 30, 2014 Collateralized Loan Obligations [Member] Fair Value, Inputs, Level 2 [Member]	Sep. 30, 2013 Collateralized Loan Obligations [Member] Fair Value, Inputs, Level 2 [Member]	Sep. 30, 2014 Other Assets [Member] Fair Value, Measurements, Nonrecurring [Member]	Sep. 30, 2014 Other Assets [Member] Fair Value, Measurements, Nonrecurring [Member]	Dec. 31, 2013 Other Assets [Member] Fair Value, Measurements, Nonrecurring [Member]	Sep. 30, 2014 Other Assets [Member] Property Subject to Operating Lease [Member] Fair Value, Measurements, Nonrecurring [Member]	Sep. 30, 2013 Other Assets [Member] Property Subject to Operating Lease [Member] Fair Value, Measurements, Nonrecurring [Member]	Sep. 30, 2014 Other Assets [Member] Property Subject to Operating Lease [Member] Fair Value, Measurements, Nonrecurring [Member]	Sep. 30, 2013 Other Assets [Member] Property Subject to Operating Lease [Member] Fair Value, Measurements, Nonrecurring [Member]
Asset Impairment Charges																			$ 49	$ 62	$ 61	$ 49	$ 38	$ 57	$ 39
Fair Value, Option, Credit Risk, Gains (Losses) on Assets															0	1	0	2
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3					(64)	(50)	(181)	159
Investments, Fair Value Disclosure									109	103	402	402	421	336
Derivative Assets	1,237	[1]	1,384	[1]
Derivative Liabilities	$ 360	[2]	$ 525	[2]

[1] At September 30, 2014, $1.2 billion, net of $312 million offsetting cash collateral, is recognized in trading assets and derivatives within the Company's Consolidated Balance Sheets. At December 31, 2013, $1.4 billion, net of $457 million offsetting cash collateral, is recognized in trading assets and derivatives within the Company's Consolidated Balance Sheets.

[2] At September 30, 2014, $360 million, net of $876 million offsetting cash collateral, is recognized in trading liabilities and derivatives within the Company's Consolidated Balance Sheets. At December 31, 2013, $525 million, net of $864 million offsetting cash collateral, is recognized in trading liabilities and derivatives within the Company's Consolidated Balance Sheets.