Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Disaggregation of Revenue [Line Items]
Other operating income (in-scope of Topic 606)	$ 1,536	$ 1,441	$ 4,397	$ 4,251
Other operating income (out-of-scope of Topic 606)	7,137	12,414	20,052	28,271
Total Other Operating Income	8,673	13,855	24,449	32,522
Bankcard fees
Disaggregation of Revenue [Line Items]
Other operating income (in-scope of Topic 606)	724	664	2,056	1,903
Service charges on deposit accounts
Disaggregation of Revenue [Line Items]
Other operating income (in-scope of Topic 606)	407	406	1,137	1,254
Other
Disaggregation of Revenue [Line Items]
Other operating income (in-scope of Topic 606)	$ 405	$ 371	$ 1,204	$ 1,094