Loans Held for Investment, net - Gross Balance of Loans by Risk Category (Detail) - USD ($) $ in Thousands		Sep. 30, 2015	Dec. 31, 2014
Financing Receivable, Recorded Investment [Line Items]
Total gross loans		$ 1,560,012	$ 1,583,105
Pass
Financing Receivable, Recorded Investment [Line Items]
Total gross loans		1,464,353	1,465,224
Special mention
Financing Receivable, Recorded Investment [Line Items]
Total gross loans		11,381	6,243
Total pass and special mention rated loans
Financing Receivable, Recorded Investment [Line Items]
Total gross loans		1,475,734	1,471,467
Substandard rated loans, excluding TDR accrual
Financing Receivable, Recorded Investment [Line Items]
Total gross loans	[1]	12,646	16,353
TDRs-accrual
Financing Receivable, Recorded Investment [Line Items]
Total gross loans	[2]	56,921	60,170
Nonaccrual
Financing Receivable, Recorded Investment [Line Items]
Total gross loans		14,711	35,115
Impaired loans
Financing Receivable, Recorded Investment [Line Items]
Total gross loans		$ 71,632	$ 95,285

[1] Includes residential and consumer loans identified as substandard that are not on nonaccrual.

[2] Includes pass rated TDR accruing loans of $54.1 million and $55.4 million at September 30, 2015 and December 31, 2014, respectively.