FAIR VALUE MEASUREMENTS - Summary of Financial Assets and Financial Liabilities Measured at Fair Value on a Recurring Basis (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016	Jun. 30, 2016	Dec. 31, 2015
Assets
Loans held for sale	$ 1,608,025	$ 1,858,358
Pledged securities	92,401	84,850	$ 78,491	$ 72,190
Derivative assets	24,991	61,824
Liabilities
Derivative liabilities	500	4,396
Recurring
Assets
Loans held for sale	1,608,025	1,858,358
Pledged securities	92,401	84,850
Derivative assets	24,991	61,824
Total financial assets	1,725,417	2,005,032
Liabilities
Derivative liabilities	500	4,396
Total financial liabilities	500	4,396
Level 1 | Recurring
Assets
Pledged securities	92,401	84,850
Total financial assets	92,401	84,850
Level 2 | Recurring
Assets
Loans held for sale	1,608,025	1,858,358
Total financial assets	1,608,025	1,858,358
Level 3 | Recurring
Assets
Derivative assets	24,991	61,824
Total financial assets	24,991	61,824
Liabilities
Derivative liabilities	500	4,396
Total financial liabilities	$ 500	$ 4,396