PREMISES AND EQUIPMENT (Details) - USD ($) $ in Thousands	24 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	$ 738,967	$ 725,984
Accumulated depreciation and amortization	433,406	417,859
Premises and equipment, net	305,561	308,125
Land [Member]
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	78,941	78,908
Buildings And Improvements [Member]
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	$ 337,216	335,304
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	$ 10,603	10,795
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	$ 291,842	279,854
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	$ 20,365	$ 21,123