PREMISES AND EQUIPMENT (Details) (USD $)	3 Months Ended
	Mar. 31, 2014	Dec. 31, 2013
Premises and equipment disclosures
Premises and equipment, gross	$ 258,900,000	$ 247,500,000
Accumulated depreciation and amortization	(73,700,000)	(69,800,000)
Premises and equipment, net	185,214,000	177,710,000
Net increase in premises and equipment	$ 7,500,000
Furniture and Fixtures
Premises and equipment disclosures
Estimated useful life	7 years
Office Equipment
Premises and equipment disclosures
Estimated useful life	5 years
Building and Building Improvements
Premises and equipment disclosures
Estimated useful life	25 years