Fair Value Measurements - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net fair value of the interest rate lock commitments	$ 60
Increases in the fair value of the interest rate lock commitments, due to decrease in current interest rates of 25 bp	24
Increases in the fair value of the interest rate lock commitments, due to decrease in current interest rates of 50 bp	39
Decreases in the fair value of the interest rate lock commitments, due to increase in current interest rates of 25 bp	32
Decreases in the fair value of the interest rate lock commitments, due to increase in current interest rates of 50 bp	69
Decrease in fair value of interest rate lock commitments, due to 10% adverse changes in the assumed loan closing rates	6
Decrease in fair value of interest rate lock commitments, due to 20% adverse changes in the assumed loan closing rates	12
Increase in fair value of interest rate lock commitments, due to 10% favorable changes in the assumed loan closing rates	6
Increase in fair value of interest rate lock commitments, due to 20% favorable changes in the assumed loan closing rates	12
Commercial loans transferred from the portfolio to loans held for sale	62	143	650
Existing loans held for sale, further adjusted	2,856	2,751
Residential loans transferred to the Bancorp's portfolio	77	32	160
Net impact related to fair value adjustments	1
Fair Value Option Changes In Fair Value Gain Loss1	157	123
Incremental Share Purchase Option	20
Fair Value Changes Included In Earnings For Instruments No Longer Held	849	341
Fair Value, Inputs, Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commercial loans transferred from the portfolio to loans held for sale	16
Residential Mortgage Loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Existing loans held for sale, further adjusted	12
The fair value of loans	3	3
Other Real Estate Owned [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net impact related to fair value adjustments	57	71
Nonrecurring Losses Included As Charge-Offs	$ 17	$ 100