Premises and Equipment (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Property, Plant and Equipment
Premises and equipment, gross	$ 303,401	$ 303,154
Less accumulated depreciation	(123,711)	(115,589)
Premises and equipment, net	179,690	187,565
Land
Property, Plant and Equipment
Premises and equipment, gross	37,581	38,917
Buildings and improvements
Property, Plant and Equipment
Premises and equipment, gross	196,950	195,549
Furniture and equipment
Property, Plant and Equipment
Premises and equipment, gross	$ 68,870	$ 68,688