Summary of Significant Accounting Policies - Schedule of Net Warehouse Interest Income (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Interest Income Expense Net Line Items
Net warehouse interest income	$ 3,580	$ 6,610	$ 10,311	$ 10,964
Loans Held for Sale
Interest Income Expense Net Line Items
Warehouse interest income	7,298	11,063	20,821	18,472
Warehouse interest expense	(5,168)	(6,764)	(13,516)	(11,719)
Net warehouse interest income	2,130	4,299	7,305	6,753
Loans Held for Investment
Interest Income Expense Net Line Items
Warehouse interest income	2,630	3,770	5,453	6,827
Warehouse interest expense	(1,180)	(1,459)	(2,447)	(2,616)
Net warehouse interest income	$ 1,450	$ 2,311	$ 3,006	$ 4,211