DEPOSITS (Deposit Liabilities) (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Deposits:
Non-interest-bearing accounts	$ 3,036,330	$ 2,619,618
Interest-bearing checking	767,460	1,159,846
Regular savings accounts	1,327,558	1,284,642
Money market accounts	1,610,640	1,637,092
Total transaction and saving accounts	6,741,988	6,701,198
Certificates of deposit less than or equal to the FDIC insured limit of $250,000	1,030,755	1,168,495
Certificates of deposit greater than the FDIC insured limit of $250,000	257,118	185,375
Total certificates of deposit	1,287,873	1,353,870
Total deposits	8,029,861	8,055,068
Included in total deposits:
Public fund transaction accounts	206,240	209,430
Public fund interest-bearing certificates	29,983	31,281
Total public deposits	236,223	240,711
Total brokered deposits	$ 135,603	$ 162,936