XML 74 R61.htm IDEA: XBRL DOCUMENT v3.8.0.1
Loans Receivable and Allowance for Loan Losses - Summary of Loans Receivable by Portfolio Segment and Impairment Method (Detail) - USD ($)
$ in Thousands
Dec. 31, 2017
Dec. 31, 2016
Financing Receivable, Allowance for Credit Losses [Line Items]    
Individually evaluated for impairment $ 52,041 $ 52,019
Collectively evaluated for impairment 7,276,922 6,952,289
Total gross loans 7,328,963 7,004,308
Mortgage Portfolio Segment [Member]    
Financing Receivable, Allowance for Credit Losses [Line Items]    
Individually evaluated for impairment 28,459 29,551
Collectively evaluated for impairment 5,081,409 4,827,558
Total gross loans 5,109,868 4,857,109
Commercial Portfolio Segment [Member]    
Financing Receivable, Allowance for Credit Losses [Line Items]    
Individually evaluated for impairment 21,223 20,255
Collectively evaluated for impairment 1,723,915 1,610,189
Total gross loans 1,745,138 1,630,444
Consumer Portfolio Segment [Member]    
Financing Receivable, Allowance for Credit Losses [Line Items]    
Individually evaluated for impairment 2,359 2,213
Collectively evaluated for impairment 471,598 514,542
Total gross loans $ 473,957 $ 516,755