SUPPLEMENTAL CASH FLOW INFORMATION - Supplemental Cash Flow Information (Detail) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2016	Jun. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Cash paid for:
Interest on borrowings				$ 104,031	$ 70,016
Income tax				1,878	3,404
Non-cash investing and financing activities:
Additions to other real estate owned				37,606	44,415
Additions to auto repossesions				42,934	57,901
Loan securitizations				238,599	213,391
Capitalization of servicing assets	$ 1,420		$ 1,242	3,878	3,789
Loans held for investment transferred to held for sale				10,332	0
Common Stock Issued In Exchange For Trust Preferred Securities Value				0	5,628
Trust Preferred Securities Exchanged Liquidation Value		$ 5,300		0	5,303
Transfer Of Loans Held For Sale To Portfolio Loans 1				1,321	0
Deposits [Member]
Non-cash investing and financing activities:
Liabilities Assumed1				0	(523,517)
Loans [Member]
Non-cash investing and financing activities:
Fair Value Of Assets Acquired				0	311,410
Property Plant And Equipment [Member]
Non-cash investing and financing activities:
Fair Value Of Assets Acquired				0	5,450
Core Deposits [Member]
Non-cash investing and financing activities:
Fair Value Of Assets Acquired				$ 0	$ 5,820