Loans Receivable, Net - Recorded Investment in Residential and Consumer Loans Based on Payment Activity (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Financing Receivable, Recorded Investment [Line Items]
Non-performing	$ 18,392	$ 45,360
Total loans	1,659,085	1,571,579
Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Non-performing	1,811	4,328
Total loans	199,842	200,683
Residential Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	779,718	781,406
Residential Real Estate [Member] | Originated by Bank [Member]
Financing Receivable, Recorded Investment [Line Items]
Performing	661,277	638,936
Non-performing	1,881	16,145
Total loans	663,158	655,081
Residential Real Estate [Member] | Originated by Mortgage Company [Member]
Financing Receivable, Recorded Investment [Line Items]
Performing	72,655	82,296
Non-performing	1,384	10,589
Total loans	74,039	92,885
Residential Real Estate [Member] | Originated by Mortgage Company - Non-Prime [Member]
Financing Receivable, Recorded Investment [Line Items]
Performing	884	1,139
Non-performing	494	1,479
Total loans	1,378	2,618
Residential Real Estate [Member] | Residential Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Performing	41,143	30,821
Total loans	41,143	30,821
Residential Real Estate [Member] | Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Performing	198,031	196,355
Non-performing	1,811	4,328
Total loans	$ 199,842	$ 200,683