LOAN PORTFOLIO - Loans Held for Investment on Which Accrual of Interest Income had been Discontinued (Detail) - Nonperforming Financial Instruments [Member] - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Non-performing loans:
Total non-performing loans held for investment	$ 315,973	$ 489,554
Commercial mortgage [Member]
Non-performing loans:
Total non-performing loans held for investment	109,536	156,493
Commercial Portfolio Segment [Member] | Construction Loans [Member]
Non-performing loans:
Total non-performing loans held for investment	0	35,100
Commercial Portfolio Segment [Member] | Construction Loans [Member] | Land [Member]
Non-performing loans:
Total non-performing loans held for investment	6,260	15,026
Commercial Portfolio Segment [Member] | Commercial and Industrial [Member}
Non-performing loans:
Total non-performing loans held for investment	30,382	85,839
Residential Portfolio Segment [Member] | Construction Loans [Member]
Non-performing loans:
Total non-performing loans held for investment	2,102	1,987
Consumer Portfolio Segment [Member] | Auto loans [Member]
Non-performing loans:
Total non-performing loans held for investment	11,212	10,211
Consumer Portfolio Segment [Member] | Other consumer loans [Member]
Non-performing loans:
Total non-performing loans held for investment	7,865	5,370
Finance leases [Member]
Non-performing loans:
Total non-performing loans held for investment	1,329	1,237
Residential Mortgage [Member]
Non-performing loans:
Total non-performing loans held for investment	$ 147,287	$ 178,291