FAIR VALUE, Carrying Amounts and Estimated Fair Values of Other Financial Instruments (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Carrying Value [Member]
Financial assets [Abstract]
Net loans	$ 4,858,276	$ 4,755,974
Financial liabilities [Abstract]
Deposits	6,957,854	6,873,474
Borrowings	267,600	301,300
Subordinated debt held by unconsolidated subsidiary trusts	102,158	102,146
Fair Value [Member]
Financial assets [Abstract]
Net loans	4,928,960	4,808,856
Financial liabilities [Abstract]
Deposits	6,956,075	6,871,098
Borrowings	267,600	301,300
Subordinated debt held by unconsolidated subsidiary trusts	$ 80,108	$ 84,680