Non Purchased Loans - Investment and Interest Income Recognized on Impaired Loans (Details) - Non purchased loans and leases - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Investment and interest income recognized on impaired loans
Average Recorded Investment	$ 26,216	$ 19,469	$ 26,688	$ 19,937
Interest Income Recognized	142	159	433	345
Commercial, financial, agricultural
Investment and interest income recognized on impaired loans
Average Recorded Investment	1,979	1,960	2,204	2,140
Interest Income Recognized	11	8	31	8
Lease financing
Investment and interest income recognized on impaired loans
Average Recorded Investment	0	0	0	0
Interest Income Recognized	0	0	0	0
Real estate – construction
Investment and interest income recognized on impaired loans
Average Recorded Investment	9,725	897	9,621	861
Interest Income Recognized	42	33	109	36
Real estate – 1-4 family mortgage
Investment and interest income recognized on impaired loans
Average Recorded Investment	8,136	8,897	8,388	8,944
Interest Income Recognized	51	71	174	165
Real estate – commercial mortgage
Investment and interest income recognized on impaired loans
Average Recorded Investment	6,258	7,575	6,354	7,844
Interest Income Recognized	37	46	117	134
Installment loans to individuals
Investment and interest income recognized on impaired loans
Average Recorded Investment	118	140	121	148
Interest Income Recognized	$ 1	$ 1	$ 2	$ 2