Components of deferred tax assets and liabilities (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Deferred Tax Assets Gross Abstract
Deferred Tax Assets Tax Credit Carryforwards Other	$ 12,019	$ 8,195
Deferred Tax Asset Operating Loss Carryforwards And Other Carryforwards	1,256,558	1,269,523
Deferred Tax Assets Tax Deferred Expense Compensation And Benefits	49,060	51,742
Allowance for loan losses	752,318	760,956
Deferred Tax Assets Depreciation	7,760	7,577
Other temporary differences	33,888	34,443
Total gross deferred tax assets	2,131,062	2,152,702
Deferred Tax Liabilities Abstract
Deferred Tax Liabilities Deferred Expense Deferred Policy Acquisition Cost	34,101	37,938
Deferred Tax Liabilities Parents Basis In Discontinued Operation	381	349
FDIC-assisted transaction	87,439	79,381
Deferred Tax Liabilities, Investments	13,626	3,822
Other temporary differences	13,329	13,038
Total gross deferred tax liabilities	149,514	135,082
Valuation allowance	1,239,564	1,257,977
Net deferred tax asset	741,984	759,643
Loans Member
Deferred Tax Assets Gross Abstract
Deferred Tax Assets Deferred Income	7,538	7,718
Deferred Tax Liabilities Abstract
Deferred Tax Liabilities Deferred Expense Deferred Financing Costs	638	554
Gains Losses On Sales Of Assets Member
Deferred Tax Assets Gross Abstract
Deferred Tax Assets Deferred Income	9,004	9,313
Intercompany [Member]
Deferred Tax Assets Gross Abstract
Deferred Tax Assets Deferred Income	$ 2,917	$ 3,235