Annual report pursuant to Section 13 and 15(d)

Accounting for Investments in Qualified Affordable Housing Projects - Summary of Change in Accounting Principle on Balance Sheets (Detail)

v2.4.1.9
Accounting for Investments in Qualified Affordable Housing Projects - Summary of Change in Accounting Principle on Balance Sheets (Detail) (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Jan. 01, 2012
Assets        
Cash and cash equivalents $ 158,320us-gaap_CashCashEquivalentsAndFederalFundsSold $ 179,357us-gaap_CashCashEquivalentsAndFederalFundsSold $ 268,047us-gaap_CashCashEquivalentsAndFederalFundsSold $ 201,683us-gaap_CashCashEquivalentsAndFederalFundsSold
Available-for-Sale, Estimated Fair Value 1,060,717us-gaap_AvailableForSaleSecurities 530,926us-gaap_AvailableForSaleSecurities    
Loans receivable 2,735,832us-gaap_LoansAndLeasesReceivableNetReportedAmount 2,177,498us-gaap_LoansAndLeasesReceivableNetReportedAmount    
Deferred tax assets 70,150us-gaap_DeferredTaxAssetsNet 51,888us-gaap_DeferredTaxAssetsNet    
Current tax assets 14,221us-gaap_IncomeTaxReceivable 11,953us-gaap_IncomeTaxReceivable    
Other assets   102,757us-gaap_OtherAssetsMiscellaneous    
Total assets 4,232,443us-gaap_Assets 3,054,379us-gaap_Assets    
Liabilities and Stockholders' Equity        
Liabilities 3,779,056us-gaap_Liabilities 2,654,302us-gaap_Liabilities    
Stockholders' equity 453,387us-gaap_StockholdersEquity 400,077us-gaap_StockholdersEquity 377,253us-gaap_StockholdersEquity 285,608us-gaap_StockholdersEquity
Total liabilities and stockholders' equity 4,232,443us-gaap_LiabilitiesAndStockholdersEquity 3,054,379us-gaap_LiabilitiesAndStockholdersEquity    
As Previously Reported [Member]        
Assets        
Cash and cash equivalents   179,357us-gaap_CashCashEquivalentsAndFederalFundsSold
/ us-gaap_StatementScenarioAxis
= us-gaap_ScenarioPreviouslyReportedMember
268,047us-gaap_CashCashEquivalentsAndFederalFundsSold
/ us-gaap_StatementScenarioAxis
= us-gaap_ScenarioPreviouslyReportedMember
201,683us-gaap_CashCashEquivalentsAndFederalFundsSold
/ us-gaap_StatementScenarioAxis
= us-gaap_ScenarioPreviouslyReportedMember
Available-for-Sale, Estimated Fair Value   530,926us-gaap_AvailableForSaleSecurities
/ us-gaap_StatementScenarioAxis
= us-gaap_ScenarioPreviouslyReportedMember
   
Loans receivable   2,177,498us-gaap_LoansAndLeasesReceivableNetReportedAmount
/ us-gaap_StatementScenarioAxis
= us-gaap_ScenarioPreviouslyReportedMember
   
Deferred tax assets   51,767us-gaap_DeferredTaxAssetsNet
/ us-gaap_StatementScenarioAxis
= us-gaap_ScenarioPreviouslyReportedMember
   
Current tax assets   11,769us-gaap_IncomeTaxReceivable
/ us-gaap_StatementScenarioAxis
= us-gaap_ScenarioPreviouslyReportedMember
   
Other assets   104,222us-gaap_OtherAssetsMiscellaneous
/ us-gaap_StatementScenarioAxis
= us-gaap_ScenarioPreviouslyReportedMember
   
Total assets   3,055,539us-gaap_Assets
/ us-gaap_StatementScenarioAxis
= us-gaap_ScenarioPreviouslyReportedMember
   
Liabilities and Stockholders' Equity        
Liabilities   2,654,302us-gaap_Liabilities
/ us-gaap_StatementScenarioAxis
= us-gaap_ScenarioPreviouslyReportedMember
   
Stockholders' equity   401,237us-gaap_StockholdersEquity
/ us-gaap_StatementScenarioAxis
= us-gaap_ScenarioPreviouslyReportedMember
   
Total liabilities and stockholders' equity   3,055,539us-gaap_LiabilitiesAndStockholdersEquity
/ us-gaap_StatementScenarioAxis
= us-gaap_ScenarioPreviouslyReportedMember
   
Effect of Change in Accounting Principle [Member]        
Assets        
Deferred tax assets   121us-gaap_DeferredTaxAssetsNet
/ us-gaap_StatementScenarioAxis
= us-gaap_RestatementAdjustmentMember
   
Current tax assets   184us-gaap_IncomeTaxReceivable
/ us-gaap_StatementScenarioAxis
= us-gaap_RestatementAdjustmentMember
   
Other assets   (1,465)us-gaap_OtherAssetsMiscellaneous
/ us-gaap_StatementScenarioAxis
= us-gaap_RestatementAdjustmentMember
   
Total assets   (1,160)us-gaap_Assets
/ us-gaap_StatementScenarioAxis
= us-gaap_RestatementAdjustmentMember
   
Liabilities and Stockholders' Equity        
Stockholders' equity   (1,160)us-gaap_StockholdersEquity
/ us-gaap_StatementScenarioAxis
= us-gaap_RestatementAdjustmentMember
   
Total liabilities and stockholders' equity   $ (1,160)us-gaap_LiabilitiesAndStockholdersEquity
/ us-gaap_StatementScenarioAxis
= us-gaap_RestatementAdjustmentMember