Accrued Interest and Other Assets (Narratives) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Other assets [Line Items]
Other prepaid expenses	$ 9,200	$ 16,501
Prepaid Taxes	5,700	12,500
Core deposit intangible	3,300	4,300
Other repossessed assets	3,548	3,224
Repossessed auto	3,400	3,000
Mortgage tax credits	4,277	6,277
Accrued interest receivable from moratorium	39,700
Customer Relationships Intangible [Member]
Other assets [Line Items]
Core deposit intangible	$ 1,400	$ 1,900