FAIR VALUE, Balance Sheet Grouping (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Carrying Value [Member]
Financial assets [Abstract]
Net loans	$ 4,218,321	$ 4,190,865
Financial liabilities [Abstract]
Deposits	6,086,820	5,935,264
Borrowings	566,200	338,000
Subordinated debt held by unconsolidated subsidiary trusts	102,134	102,122
Fair Value [Member]
Financial assets [Abstract]
Net loans	4,295,518	4,251,565
Financial liabilities [Abstract]
Deposits	6,085,968	5,935,690
Borrowings	566,200	338,000
Subordinated debt held by unconsolidated subsidiary trusts	$ 92,484	$ 85,189