BANK PREMISES AND EQUIPMENT (Summary of Bank Premises and Equipment) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Property, Plant and Equipment [Line Items]
Total	$ 194,016	$ 136,812
Less accumulated depreciation and amortization	58,769	53,997
Bank premises and equipment, net	135,247	82,815
Land [Member]
Property, Plant and Equipment [Line Items]
Total	31,072	23,652
Land Improvements and Buildings [Member]
Property, Plant and Equipment [Line Items]
Total	98,259	62,329
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Total	7,950	5,313
Furniture and Equipment [Member]
Property, Plant and Equipment [Line Items]
Total	47,350	36,133
Equipment Lease [Member]
Property, Plant and Equipment [Line Items]
Total		62
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Total	$ 9,385	$ 9,323