Fair Value Measurements - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended	12 Months Ended
Mar. 31, 2012	Mar. 31, 2011	Dec. 31, 2011
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net fair value of the interest rate lock commitments	$ 18
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	43
Decreases in the fair value of the interest rate lock commitments, due to increase in current interest rates of 25 bp	29
Decreases in the fair value of the interest rate lock commitments, due to increase in current interest rates of 50 bp	60
Decrease in fair value of interest rate lock commitments, due to 10% adverse changes in the assumed loan closing rates	2
Decrease in fair value of interest rate lock commitments, due to 20% adverse changes in the assumed loan closing rates	3
Increase in fair value of interest rate lock commitments, due to 10% favorable changes in the assumed loan closing rates	2
Increase in fair value of interest rate lock commitments, due to 20% favorable changes in the assumed loan closing rates	3
Commercial loans transferred from the portfolio to loans held for sale	17	43
Existing loans held for sale, further adjusted	1,429	1,017	2,751
Residential loans transferred to the Bancorp's portfolio	57	11
Net impact related to fair value adjustments		1
Fair value changes included in earnings for instruments for which the fair value option was elected	109	8
The fair value of loans	1
Fair Value Changes Included In Earnings For Instruments No Longer Held	188	18
Residential Mortgage Loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Residential loans transferred to the Bancorp's portfolio	6	10
The fair value of loans	3	5	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	17
Nonrecurring Losses Included As Charge-Offs	$ 6

Fair value changes included in earnings for instruments no longer held

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Valuation adjustments for loans held for sale and portfolio loans.

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Nonrecurring losses included as charge-offs on loans transferred to OREO

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Sensitivity Analysis of Decrease in Fair Value of Derivatives, Impact of 50 Basis Point Increase in the Interest Rate

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Sensitivity Analysis of Decrease in Fair Value of Derivatives, Impact of 10% Changes in the Assumed Loan Closing Rates

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Sensitivity Analysis of Decrease in Fair Value of Derivatives, Impact of 25 Basis Point Increase in the Interest Rate

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Sensitivity Analysis of Decrease in Fair Value of Derivatives, Impact of 20% Changes in the Assumed Loan Closing Rates

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- Definition

Fair values as of the balance sheet date of the net amount of all assets and liabilities resulting from contracts that meet the criteria of being accounted for as derivative instruments.

+ References

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-Publisher FASB

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-Paragraph 10

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This item represents, for each line item in the statement of financial position, the amounts of gains and losses from fair value changes included in earnings during the period and in which line in the income statement those gains and losses are reported. This item may also include amounts of gains and losses for other items measured at fair value, but for which the fair value option has not been elected (for instance, items required to be measured at fair value).

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- Definition

This item represents the estimated amount of gains or losses included in earnings during the period attributable to changes in instrument-specific credit risk arising from loans and other receivables held as assets.

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This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents loans held-for-sale as presented on the statement of financial position which may include mortgage loans held-for-sale, finance receivables held-for-sale, or any other loans classified as held-for-sale which are due the Company as of the balance sheet date.

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Value of loans held-for-sale transferred to loans held in the entity's portfolio in noncash transactions.

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Value of loans and leases held in the entity's portfolio transferred to loans and leases held-for-sale in noncash transactions.

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