Premises and Equipment Components of Premises and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Subtotal	$ 105,569	$ 93,938
Less: accumulated depreciation	60,157	56,298
Premises and equipment, net	45,412	37,640
Leasehold improvements
Property, Plant and Equipment [Line Items]
Subtotal	50,489	51,161
Furniture, fixtures, and equipment
Property, Plant and Equipment [Line Items]
Subtotal	51,921	39,618
Buildings
Property, Plant and Equipment [Line Items]
Subtotal	$ 3,159	$ 3,159