Acquisition Acquisition (Details) - USD ($) $ in Thousands	May 01, 2018	Sep. 30, 2018	Dec. 31, 2017
Business Combinations [Abstract]
Payments to Acquire Businesses, Gross	$ 17,400
Business Combination, Consideration Transferred	41,561
Payments to Acquire a Business, Total Payment	58,961
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents	18,105
Business Combination Recognized Identifiable Assets Acquired and Liabilities Assumed, Federal Home Loan Bank Stock	3,261
Business Combination, Acquired Receivable, Fair Value	184,506
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment	409
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles	1,248
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Prepaid Expense and Other Assets	1,747
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets	209,276
Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Deposits	141,281
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Long-term Debt	22,988
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Other	5,068
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities	169,337
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net	39,939
Goodwill	$ 19,022	$ 274,202	$ 255,353