Fair Value - Significant Unobservable Inputs Used for Assets Measured at Fair Value on Non-Recurring Basis (Detail) - Real Estate Owned, Net [Member]	6 Months Ended	12 Months Ended
	Jun. 30, 2015	Dec. 31, 2014
Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Real estate owned, net	0.00%	0.00%
Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Real estate owned, net	70.52%	59.58%
Weighted Average [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Real estate owned, net	9.15%	8.04%