Loans Held for Investment, net - Gross Loans Modified in TDR by Class and by Type of Modification (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Financing Receivable, Impaired [Line Items]
Principal and Interest to Interest Only	$ 0	$ 175
Interest Rate Reduction	845	1,103
Interest Rate Reduction To Below Market Rate	288	1,254
Other	1,221	1,339
Total	2,354	3,871
Land and construction
Financing Receivable, Impaired [Line Items]
Principal and Interest to Interest Only		0
Interest Rate Reduction		63
Interest Rate Reduction To Below Market Rate		0
Other		347
Total		410
Multi-family
Financing Receivable, Impaired [Line Items]
Principal and Interest to Interest Only		0
Interest Rate Reduction		0
Interest Rate Reduction To Below Market Rate		921
Other		262
Total		1,183
Retail/office
Financing Receivable, Impaired [Line Items]
Principal and Interest to Interest Only	0
Interest Rate Reduction	0
Interest Rate Reduction To Below Market Rate	0
Other	510
Total	510
Other commercial real estate
Financing Receivable, Impaired [Line Items]
Principal and Interest to Interest Only		0
Interest Rate Reduction		0
Interest Rate Reduction To Below Market Rate		214
Other		42
Total		256
Residential
Financing Receivable, Impaired [Line Items]
Principal and Interest to Interest Only	0	175
Interest Rate Reduction	380	788
Interest Rate Reduction To Below Market Rate	78	119
Other	124	538
Total	582	1,620
Commercial and industrial
Financing Receivable, Impaired [Line Items]
Principal and Interest to Interest Only	0	0
Interest Rate Reduction	11	0
Interest Rate Reduction To Below Market Rate	0	0
Other	0	97
Total	11	97
Consumer loans | Other consumer
Financing Receivable, Impaired [Line Items]
Principal and Interest to Interest Only	0	0
Interest Rate Reduction	454	252
Interest Rate Reduction To Below Market Rate	210	0
Other	587	53
Total	$ 1,251	$ 305