PREMISES AND EQUIPMENT (Details) - USD ($) $ in Thousands	24 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	$ 725,984	$ 702,533
Accumulated depreciation and amortization	417,859	397,590
Premises and equipment, net	308,125	304,943
Land [Member]
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	78,908	78,021
Buildings And Improvements [Member]
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	$ 335,304	331,277
Buildings And Improvements [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated Useful Life (Years)	10 years
Buildings And Improvements [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated Useful Life (Years)	40 years
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	$ 10,795	9,653
Leasehold Improvements [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated Useful Life (Years)	10 years
Leasehold Improvements [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated Useful Life (Years)	39 years
Equipment, Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	$ 279,854	275,607
Equipment, Furniture and Fixtures [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated Useful Life (Years)	3 years
Equipment, Furniture and Fixtures [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated Useful Life (Years)	12 years
Construction In Progress [Member]
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	$ 21,123	$ 7,975