Loans Receivable, Net - Additional Information (Detail) - USD ($)		3 Months Ended		9 Months Ended		12 Months Ended
	Jul. 31, 2015	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans with non-accrual of interest		$ 24,394,000		$ 24,394,000		$ 18,307,000
Financing receivables 90 days past due and still accruing		0		0
Impaired loans on non-accrual commercial real estate, multi-family, land, construction and commercial loans				250,000
Impaired loan portfolio total		45,573,000		45,573,000		36,979,000
Allocation in allowance for loan losses		2,400,000		2,400,000		2,161,000
Average balance of impaired loans		46,211,000	$ 41,749,000	40,909,000	$ 42,162,000
Troubled debt restructuring loans		30,754,000		30,754,000		23,493,000
Troubled debt restructuring loans with accrual interest		26,935,000		26,935,000		21,462,000
Non-accrual loan total troubled debt restructurings		3,819,000				2,031,000
Specific reserves to loans accruing troubled debt restructurings		587,000		587,000		419,000
Colonial American Bank [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	$ 0
Residential Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans with non-accrual of interest		5,481,000		5,481,000		3,115,000
Recorded investment in mortgage and consumer loans collateralized, foreclosure amount		2,852,000		2,852,000
Foreclosed property held		3,104,000		3,104,000
Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans with non-accrual of interest		17,057,000		17,057,000		$ 12,758,000
Loans classified as troubled debt restructurings		$ 3,900,000		$ 3,900,000