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) (Residential mortgage-backed securities [Member])	12 Months Ended
	Dec. 31, 2013
Fair Value Assets Measured On Recurring Basis [Line Items]
Valuation technique to measure fair value	Discounted cash flow
Significant Unobservable Inputs (Level 3) [Member]
Fair Value Assets Measured On Recurring Basis [Line Items]
Prepayment rate, Weighted Average of unobservable inputs	17.60%
Default rate, Weighted Average of unobservable inputs	9.30%
Loss severity, Weighted Average of unobservable inputs	37.00%
Significant Unobservable Inputs (Level 3) [Member] | Minimum [Member]
Fair Value Assets Measured On Recurring Basis [Line Items]
Prepayment rate, Range of unobservable inputs	4.60%
Default rate, Range of unobservable inputs	3.10%
Loss severity, Range of unobservable inputs	25.80%
Significant Unobservable Inputs (Level 3) [Member] | Maximum [Member]
Fair Value Assets Measured On Recurring Basis [Line Items]
Prepayment rate, Range of unobservable inputs	25.90%
Default rate, Range of unobservable inputs	25.60%
Loss severity, Range of unobservable inputs	46.20%