Schedule of Repurchase Agreements Obligation by Type of Collateral (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase Agreements	$ 40,929	$ 29,907
Gross and Net Amounts of Liabilities Presented in the Statement of Financial Condition	55,946	38,560
Net Amount, Liabilities	791	97
Asset-backed Securities
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase Agreements	39,959
Us Treasury And Agencies
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase Agreements	970
Repurchase Agreements
Assets Sold under Agreements to Repurchase [Line Items]
Gross and Net Amounts of Liabilities Presented in the Statement of Financial Condition	40,929	$ 29,907
Net Amount, Liabilities	0
Overnight and Continuous
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase Agreements	970
Overnight and Continuous | Us Treasury And Agencies
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase Agreements	970
Overnight and Continuous | Repurchase Agreements
Assets Sold under Agreements to Repurchase [Line Items]
Net Amount, Liabilities	0
Up to 30 Days
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase Agreements	39,959
Up to 30 Days | Asset-backed Securities
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase Agreements	39,959
Up to 30 Days | Repurchase Agreements
Assets Sold under Agreements to Repurchase [Line Items]
Net Amount, Liabilities	0
30 - 90 Days | Repurchase Agreements
Assets Sold under Agreements to Repurchase [Line Items]
Net Amount, Liabilities	0
Greater than 90 Days | Repurchase Agreements
Assets Sold under Agreements to Repurchase [Line Items]
Net Amount, Liabilities	$ 0