Changes in the Allowance for Loan Losses (Detail) (USD $) In Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of period	$ 736,505		$ 793,225
Provision for loan losses	144,317		219,636
Recoveries	37,874		63,129
Charge-offs	(171,849)		(342,950)
Recoveries related to loans transferred to loans held-for-sale			13,807
Balance at end of period	746,847		746,847
Non Covered under Loss Sharing Agreements With FDIC | Loans
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of period	727,346		793,225
Provision for loan losses	95,712		155,474
Recoveries	37,874		63,129
Charge-offs	(171,254)		(335,957)
Recoveries related to loans transferred to loans held-for-sale			13,807
Balance at end of period	689,678		689,678
Covered under Loss Sharing Agreements with FDIC | Loans
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of period	9,159
Provision for loan losses	48,605		64,162
Charge-offs	(595)		(6,993)
Balance at end of period	57,169		57,169
Loans
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of period	736,505	1,277,036	793,225	1,261,204
Provision for loan losses	144,317	202,258	219,636	442,458
Recoveries	37,874	31,839	63,129	51,312
Charge-offs	(171,849)	(234,117)	(342,950)	(477,958)
Recoveries related to loans transferred to loans held-for-sale			13,807
Balance at end of period	$ 746,847	$ 1,277,016	$ 746,847	$ 1,277,016