DEPOSITS - Components of Interest Bearing Deposits (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Deposits [Abstract]
Interest-bearing demand deposits	$ 2,048,839	$ 1,697,055
Money market accounts	2,731,314	1,479,931
Savings accounts	1,118,175	823,618
Certificates of deposit of under $100,000	1,300,733	633,372
Certificates of deposit of $100,000 through $250,000	249,502	250,868
Certificates of deposit of more than $250,000	410,958	297,117
Total interest-bearing deposits	$ 7,859,521	$ 5,181,961