Activity in the FDIC Loss Share Indemnification Asset (Detail) (USD $) In Thousands	6 Months Ended
	Jun. 30, 2011		Jun. 30, 2010
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Line Items]
Beginning Balance	$ 2,318,183
FDIC loss share indemnification asset recorded at business combination			2,337,748
Accretion of loss share indemnification asset, net	31,389		17,665
Credit impairment losses to be covered under loss sharing agreements	51,329
Decrease due to reciprocal accounting on the discount accretion for loans and unfunded commitments accounted for under ASC Subtopic 310-20	(30,003)		(32,702)
Credit impairment losses reclassified to claims receivables, net of recoveries	(579,294)
Other net benefits attributable to FDIC loss sharing agreements	13,156		7,695
Claims receivables filed with FDIC and outstanding	545,416	[1]
Ending Balance	$ 2,350,176		$ 2,330,406

[1] Represent claims filed with the FDIC for losses on covered assets and reimbursable expenses. The Corporation received payment from the FDIC amounting to $545 million in July 2011.