Loans Receivable and Allowance for Loan Losses (Summary of Allowance for Loan Losses by Portfolio Segment and Impairment Classification) (Detail) - USD ($) $ in Thousands	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually evaluated for impairment	$ 2,313		$ 2,271
Collectively evaluated for impairment	58,620		59,153
Total	60,933	$ 62,191	61,424	$ 59,624	$ 61,110	$ 61,734
Mortgage Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually evaluated for impairment	2,146		2,086
Collectively evaluated for impairment	29,488		30,008
Total	31,634	30,849	32,094	31,824	32,886	31,977
Commercial Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually evaluated for impairment	81		91
Collectively evaluated for impairment	26,218		25,738
Total	26,299	28,255	25,829	22,840	23,697	24,381
Consumer Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually evaluated for impairment	86		94
Collectively evaluated for impairment	2,914		3,407
Total	$ 3,000	$ 3,087	$ 3,501	$ 4,570	$ 4,277	$ 4,881