Premises and Equipment, Net (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Property, Plant and Equipment [Line Items]
Premises and equipment before accumulated depreciation	$ 185,002	$ 181,235
Accumulated depreciation	96,176	91,977
Total premises and equipment	88,826	89,258
Rental expense	7,900	8,000	$ 7,500
Future Minimum Rental Payments [Abstract]
2016	7,367
2017	7,015
2018	6,356
2019	5,803
2020	4,977
Thereafter	21,628
Total	53,146
Land, Buildings and Improvements [Member]
Property, Plant and Equipment [Line Items]
Premises and equipment before accumulated depreciation	125,428	122,400
Equipment [Member]
Property, Plant and Equipment [Line Items]
Premises and equipment before accumulated depreciation	$ 59,574	$ 58,835
Equipment [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	3 years
Equipment [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	10 years
Building and Improvements [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	15 years
Building and Improvements [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	40 years