FAIR VALUE MEASUREMENTS - Summary of Financial Assets and Financial Liabilities Measured at Fair Value on a Recurring Basis (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Assets
Loans held for sale	$ 1,858,358	$ 2,499,111
Pledged securities	84,850	72,190	$ 67,719	$ 49,651
Derivative assets	61,824	11,678
Liabilities
Derivative liabilities	4,396	1,333
Recurring
Assets
Loans held for sale	1,858,358	2,499,111
Pledged securities	84,850	72,190
Derivative assets	61,824	11,678
Total financial assets	2,005,032	2,582,979
Liabilities
Derivative liabilities	4,396	1,333
Total financial liabilities	4,396	1,333
Level 1 | Recurring
Assets
Pledged securities	84,850	72,190
Total financial assets	84,850	72,190
Level 2 | Recurring
Assets
Loans held for sale	1,858,358	2,499,111
Total financial assets	1,858,358	2,499,111
Level 3 | Recurring
Assets
Derivative assets	61,824	11,678
Total financial assets	61,824	11,678
Liabilities
Derivative liabilities	4,396	1,333
Total financial liabilities	$ 4,396	$ 1,333