Fair Value Measurement of Assets and Liabilities - Schedule of Quantitative Information about Level 3 Inputs Used to Measure Fair Value of Available for Sale Securities (Detail) - Significant Unobservable Inputs (Level 3) - Residential mortgage-backed securities	6 Months Ended
	Jun. 30, 2016
Fair Value Assets Measured On Recurring Basis
Valuation technique to measure fair value	Discounted cash flow
Prepayment rate, Weighted Average of unobservable inputs	10.10%
Default rate, Weighted Average of unobservable inputs	7.90%
Loss severity, Weighted Average of unobservable inputs	60.50%
Minimum
Fair Value Assets Measured On Recurring Basis
Prepayment rate, Range of unobservable inputs	0.00%
Default rate, Range of unobservable inputs	3.60%
Loss severity, Range of unobservable inputs	45.40%
Maximum
Fair Value Assets Measured On Recurring Basis
Prepayment rate, Range of unobservable inputs	20.20%
Default rate, Range of unobservable inputs	16.20%
Loss severity, Range of unobservable inputs	66.30%