DEPOSITS (Deposit Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Deposit Liabilities [Line Items]
Non-interest-bearing checking	$ 3,140,451	$ 2,619,618
Interest-bearing checking	914,484	1,159,846
Regular savings accounts	1,523,391	1,284,642
Money market accounts	1,497,755	1,637,092
Total interest-bearing transaction and savings accounts	3,935,630	4,081,580
Time Deposits, $250,000 or less	884,403	1,168,495
Time Deposits, More than $250,000	160,930	185,375
Interest-bearing certificates	1,045,333	1,353,870
Total deposits	8,121,414	8,055,068
Included in total deposits:
Public fund transaction accounts	221,765	209,430
Public fund interest-bearing certificates	25,650	31,281
Total public deposits	247,415	240,711
Total brokered deposits	34,074	162,936
Related Party Deposit Liabilities	$ 7,200	$ 6,600