Premises and Equipment, Net - Premises and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Premises and Equipment, Net, by Type [Abstract]
Total cost of premises and equipment	$ 426,166	$ 418,854
Less accumulated depreciation and amortization	230,510	218,073
Premises and equipment, net	195,656	200,781
Land [Member]
Premises and Equipment, Net, by Type [Abstract]
Total cost of premises and equipment	57,334	57,794
Building and Leasehold Improvements [Member]
Premises and Equipment, Net, by Type [Abstract]
Total cost of premises and equipment	200,475	198,739
Furniture and Equipment [Member]
Premises and Equipment, Net, by Type [Abstract]
Total cost of premises and equipment	$ 168,357	$ 162,321