Revenue Recognition - Schedule of Disaggregation of Noninterest Income (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]
Noninterest Income (in-scope of ASC 606)	$ 16,819	$ 16,138	$ 49,446	$ 47,475
Noninterest Income (out-of-scope of ASC 606)	1,784	1,064	8,145	4,417
Total Noninterest Income	18,603	17,202	57,591	51,892
Noninterest income (out-of-scope of ASC 606), gain on sale of fixed asset			2,900
Commissions and Fees
Disaggregation of Revenue [Line Items]
Noninterest Income (in-scope of ASC 606)	7,388	7,085	21,128	20,363
Installment Billing
Disaggregation of Revenue [Line Items]
Noninterest Income (in-scope of ASC 606)	210	0	99	0
Refund of Commissions
Disaggregation of Revenue [Line Items]
Noninterest Income (in-scope of ASC 606)	(50)	0	(67)	0
Contract Liabilities/Deferred Revenue
Disaggregation of Revenue [Line Items]
Noninterest Income (in-scope of ASC 606)	(1)	(57)	(175)	(434)
Contingent commissions
Disaggregation of Revenue [Line Items]
Noninterest Income (in-scope of ASC 606)	356	654	1,699	1,963
Subtotal Insurance Revenues
Disaggregation of Revenue [Line Items]
Noninterest Income (in-scope of ASC 606)	7,903	7,682	22,684	21,892
Trust and Asset Management
Disaggregation of Revenue [Line Items]
Noninterest Income (in-scope of ASC 606)	2,744	2,441	8,139	7,381
Mutual Fund & Investment Income
Disaggregation of Revenue [Line Items]
Noninterest Income (in-scope of ASC 606)	1,353	1,421	4,226	4,163
Subtotal Investment Service Income
Disaggregation of Revenue [Line Items]
Noninterest Income (in-scope of ASC 606)	4,097	3,862	12,365	11,544
Service Charges on Deposit Accounts
Disaggregation of Revenue [Line Items]
Noninterest Income (in-scope of ASC 606)	2,088	2,125	6,300	6,337
Card Services Income
Disaggregation of Revenue [Line Items]
Noninterest Income (in-scope of ASC 606)	2,442	2,190	7,209	6,875
Other
Disaggregation of Revenue [Line Items]
Noninterest Income (in-scope of ASC 606)	$ 289	$ 279	$ 888	$ 827