Loans - Impaired Loans by Class (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Impaired loans with a valuation allowance
Schedule of Impaired loans by classes
Recorded Investment	$ 68,820	$ 74,740
Unpaid Principal Balance	77,882	85,264
Related Valuation Allowance	5,640	9,392
Impaired loans with no valuation allowance
Schedule of Impaired loans by classes
Recorded Investment	36,079	32,129
Unpaid Principal Balance	45,739	38,794
Related Valuation Allowance	0	0
Total Impaired Loans
Schedule of Impaired loans by classes
Recorded Investment	104,899	106,869
Unpaid Principal Balance	123,621	124,058
Related Valuation Allowance	5,640	9,392
Commercial | Impaired loans with a valuation allowance
Schedule of Impaired loans by classes
Recorded Investment	26,201	28,925
Unpaid Principal Balance	29,804	33,209
Related Valuation Allowance	2,468	3,128
Commercial | Impaired loans with no valuation allowance
Schedule of Impaired loans by classes
Recorded Investment	9,028	7,435
Unpaid Principal Balance	14,910	11,153
Related Valuation Allowance	0	0
Commercial | Total Impaired Loans
Schedule of Impaired loans by classes
Recorded Investment	35,229	36,360
Unpaid Principal Balance	44,714	44,362
Related Valuation Allowance	2,468	3,128
Commercial real estate | Impaired loans with a valuation allowance
Schedule of Impaired loans by classes
Recorded Investment	20,416	21,318
Unpaid Principal Balance	25,875	27,558
Related Valuation Allowance	1,251	2,102
Commercial real estate | Impaired loans with no valuation allowance
Schedule of Impaired loans by classes
Recorded Investment	22,791	20,588
Unpaid Principal Balance	26,569	23,535
Related Valuation Allowance	0	0
Commercial real estate | Total Impaired Loans
Schedule of Impaired loans by classes
Recorded Investment	43,207	41,906
Unpaid Principal Balance	52,444	51,093
Related Valuation Allowance	1,251	2,102
Real estate construction and land development | Impaired loans with a valuation allowance
Schedule of Impaired loans by classes
Recorded Investment	164	177
Unpaid Principal Balance	164	177
Related Valuation Allowance	2	4
Real estate construction and land development | Impaired loans with no valuation allowance
Schedule of Impaired loans by classes
Recorded Investment	79	80
Unpaid Principal Balance	79	80
Related Valuation Allowance	0	0
Real estate construction and land development | Total Impaired Loans
Schedule of Impaired loans by classes
Recorded Investment	243	257
Unpaid Principal Balance	243	257
Related Valuation Allowance	2	4
Residential mortgage | Impaired loans with a valuation allowance
Schedule of Impaired loans by classes
Recorded Investment	16,944	20,864
Unpaid Principal Balance	16,944	20,864
Related Valuation Allowance	1,162	3,528
Residential mortgage | Impaired loans with no valuation allowance
Schedule of Impaired loans by classes
Recorded Investment	3,607	3,252
Unpaid Principal Balance	3,607	3,252
Related Valuation Allowance	0	0
Residential mortgage | Total Impaired Loans
Schedule of Impaired loans by classes
Recorded Investment	20,551	24,116
Unpaid Principal Balance	20,551	24,116
Related Valuation Allowance	1,162	3,528
Consumer installment | Impaired loans with a valuation allowance
Schedule of Impaired loans by classes
Recorded Investment	799	879
Unpaid Principal Balance	799	879
Related Valuation Allowance	102	240
Consumer installment | Impaired loans with no valuation allowance
Schedule of Impaired loans by classes
Recorded Investment	62
Unpaid Principal Balance	62
Related Valuation Allowance	0
Consumer installment | Total Impaired Loans
Schedule of Impaired loans by classes
Recorded Investment	861	879
Unpaid Principal Balance	861	879
Related Valuation Allowance	102	240
Home equity | Impaired loans with a valuation allowance
Schedule of Impaired loans by classes
Recorded Investment	4,296	2,577
Unpaid Principal Balance	4,296	2,577
Related Valuation Allowance	655	390
Home equity | Impaired loans with no valuation allowance
Schedule of Impaired loans by classes
Recorded Investment	512	774
Unpaid Principal Balance	512	774
Related Valuation Allowance	0	0
Home equity | Total Impaired Loans
Schedule of Impaired loans by classes
Recorded Investment	4,808	3,351
Unpaid Principal Balance	4,808	3,351
Related Valuation Allowance	$ 655	$ 390