Loans - Impaired Loans by Class (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Impaired loans with a valuation allowance
Financing Receivable, Impaired [Line Items]
Recorded Investment	$ 87,204	$ 70,051
Unpaid Principal Balance	94,274	75,511
Related Valuation Allowance	11,018	6,804
Impaired loans with no valuation allowance
Financing Receivable, Impaired [Line Items]
Recorded Investment	58,497	60,822
Unpaid Principal Balance	61,586	64,378
Related Valuation Allowance	0	0
Total Impaired Loans
Financing Receivable, Impaired [Line Items]
Recorded Investment	145,701	130,873
Unpaid Principal Balance	155,860	139,889
Related Valuation Allowance	11,018	6,804
Commercial | Impaired loans with a valuation allowance
Financing Receivable, Impaired [Line Items]
Recorded Investment	28,732	20,957
Unpaid Principal Balance	31,556	23,781
Related Valuation Allowance	5,805	3,546
Commercial | Impaired loans with no valuation allowance
Financing Receivable, Impaired [Line Items]
Recorded Investment	28,775	25,093
Unpaid Principal Balance	29,586	25,934
Related Valuation Allowance	0	0
Commercial | Total Impaired Loans
Financing Receivable, Impaired [Line Items]
Recorded Investment	57,507	46,050
Unpaid Principal Balance	61,142	49,715
Related Valuation Allowance	5,805	3,546
Total commercial real estate | Impaired loans with a valuation allowance
Financing Receivable, Impaired [Line Items]
Recorded Investment	38,916	32,543
Unpaid Principal Balance	43,162	35,179
Related Valuation Allowance	3,593	1,917
Total commercial real estate | Impaired loans with no valuation allowance
Financing Receivable, Impaired [Line Items]
Recorded Investment	20,660	26,208
Unpaid Principal Balance	22,938	28,923
Related Valuation Allowance	0	0
Total commercial real estate | Total Impaired Loans
Financing Receivable, Impaired [Line Items]
Recorded Investment	59,576	58,751
Unpaid Principal Balance	66,100	64,102
Related Valuation Allowance	3,593	1,917
Real estate construction and land development | Impaired loans with a valuation allowance
Financing Receivable, Impaired [Line Items]
Recorded Investment	3,612	126
Unpaid Principal Balance	3,612	126
Related Valuation Allowance	365	11
Real estate construction and land development | Impaired loans with no valuation allowance
Financing Receivable, Impaired [Line Items]
Recorded Investment	164	111
Unpaid Principal Balance	164	111
Related Valuation Allowance	0	0
Real estate construction and land development | Total Impaired Loans
Financing Receivable, Impaired [Line Items]
Recorded Investment	3,776	237
Unpaid Principal Balance	3,776	237
Related Valuation Allowance	365	11
Residential mortgage | Impaired loans with a valuation allowance
Financing Receivable, Impaired [Line Items]
Recorded Investment	10,060	10,867
Unpaid Principal Balance	10,060	10,867
Related Valuation Allowance	790	816
Residential mortgage | Impaired loans with no valuation allowance
Financing Receivable, Impaired [Line Items]
Recorded Investment	7,235	7,537
Unpaid Principal Balance	7,235	7,537
Related Valuation Allowance	0	0
Residential mortgage | Total Impaired Loans
Financing Receivable, Impaired [Line Items]
Recorded Investment	17,295	18,404
Unpaid Principal Balance	17,295	18,404
Related Valuation Allowance	790	816
Consumer installment | Impaired loans with a valuation allowance
Financing Receivable, Impaired [Line Items]
Recorded Investment	1,594	1,126
Unpaid Principal Balance	1,594	1,126
Related Valuation Allowance	109	186
Consumer installment | Impaired loans with no valuation allowance
Financing Receivable, Impaired [Line Items]
Recorded Investment	7	377
Unpaid Principal Balance	7	377
Related Valuation Allowance	0	0
Consumer installment | Total Impaired Loans
Financing Receivable, Impaired [Line Items]
Recorded Investment	1,601	1,503
Unpaid Principal Balance	1,601	1,503
Related Valuation Allowance	109	186
Home equity | Impaired loans with a valuation allowance
Financing Receivable, Impaired [Line Items]
Recorded Investment	4,290	4,432
Unpaid Principal Balance	4,290	4,432
Related Valuation Allowance	356	328
Home equity | Impaired loans with no valuation allowance
Financing Receivable, Impaired [Line Items]
Recorded Investment	1,656	1,496
Unpaid Principal Balance	1,656	1,496
Related Valuation Allowance	0	0
Home equity | Total Impaired Loans
Financing Receivable, Impaired [Line Items]
Recorded Investment	5,946	5,928
Unpaid Principal Balance	5,946	5,928
Related Valuation Allowance	356	328
Owner-occupied | Commercial | Impaired loans with a valuation allowance
Financing Receivable, Impaired [Line Items]
Recorded Investment	20,050	14,702
Unpaid Principal Balance	22,193	16,519
Related Valuation Allowance	2,168	1,359
Owner-occupied | Commercial | Impaired loans with no valuation allowance
Financing Receivable, Impaired [Line Items]
Recorded Investment	12,057	10,971
Unpaid Principal Balance	12,895	11,601
Related Valuation Allowance	0	0
Owner-occupied | Commercial | Total Impaired Loans
Financing Receivable, Impaired [Line Items]
Recorded Investment	32,107	25,673
Unpaid Principal Balance	35,088	28,120
Related Valuation Allowance	2,168	1,359
Non-owner occupied | Commercial | Impaired loans with a valuation allowance
Financing Receivable, Impaired [Line Items]
Recorded Investment	18,080	16,833
Unpaid Principal Balance	19,966	17,452
Related Valuation Allowance	1,366	462
Non-owner occupied | Commercial | Impaired loans with no valuation allowance
Financing Receivable, Impaired [Line Items]
Recorded Investment	7,827	12,412
Unpaid Principal Balance	8,339	13,411
Related Valuation Allowance	0	0
Non-owner occupied | Commercial | Total Impaired Loans
Financing Receivable, Impaired [Line Items]
Recorded Investment	25,907	29,245
Unpaid Principal Balance	28,305	30,863
Related Valuation Allowance	1,366	462
Vacant land | Commercial | Impaired loans with a valuation allowance
Financing Receivable, Impaired [Line Items]
Recorded Investment	786	1,008
Unpaid Principal Balance	1,003	1,208
Related Valuation Allowance	59	96
Vacant land | Commercial | Impaired loans with no valuation allowance
Financing Receivable, Impaired [Line Items]
Recorded Investment	776	2,825
Unpaid Principal Balance	1,704	3,911
Related Valuation Allowance	0	0
Vacant land | Commercial | Total Impaired Loans
Financing Receivable, Impaired [Line Items]
Recorded Investment	1,562	3,833
Unpaid Principal Balance	2,707	5,119
Related Valuation Allowance	$ 59	$ 96