Number of Shares to be issued upon Exercise of Outstanding Stock-Based Awards and Remaining Shares Available for Future Issuance under all Equity Compensation Plans (Parenthetical) (Detail) (USD $)	12 Months Ended
	Dec. 31, 2009	Dec. 31, 2007	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Employee Stock Ownership Plan (ESOP) Disclosures [Line Items]
Weighted-average exercise price of the outstanding options			$ 14.25	$ 20.72	$ 45.00	$ 53.88
Number of shares to be issued based on predefined performance targets			7,260,000
Additional shares approved by shareholders included under Bancorp's 1993 Stock Purchase Plan	12,000,000	1,500,000
Performance Units
Employee Stock Ownership Plan (ESOP) Disclosures [Line Items]
Number of shares to be issued based on predefined performance targets			2,000,000
Series of Individually Immaterial Business Acquisitions
Employee Stock Ownership Plan (ESOP) Disclosures [Line Items]
Outstanding options awarded in connection with mergers and acquisitions			300,000
Weighted-average exercise price of the outstanding options			$ 13.76
2014 Incentive Compensation Plan
Employee Stock Ownership Plan (ESOP) Disclosures [Line Items]
Stock authorized for issuance			36,000,000