Loans and Allowance for Loan Losses (Troubled Debt Restructurings) (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2020 USD ($) Contract	Sep. 30, 2019 USD ($) Contract	Sep. 30, 2020 USD ($) Contract	Sep. 30, 2019 USD ($) Contract
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | Contract	80	105	280	241
Recorded Investment	$ 8,144,000	$ 14,621,000	$ 60,492,000	$ 31,352,000
Net charge-offs	$ 0	$ 0	$ 0	$ 0
Total commercial and industrial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | Contract	49	34	137	74
Recorded Investment	$ 5,758,000	$ 8,177,000	$ 18,346,000	$ 15,822,000
Total commercial and industrial | Commercial, financial and agricultural
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | Contract	42	27	118	61
Recorded Investment	$ 4,005,000	$ 4,494,000	$ 13,243,000	$ 10,107,000
Total commercial and industrial | Owner-occupied
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | Contract	7	7	19	13
Recorded Investment	$ 1,753,000	$ 3,683,000	$ 5,103,000	$ 5,715,000
Total commercial real estate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | Contract	8	9	24	23
Recorded Investment	$ 615,000	$ 1,624,000	$ 31,609,000	$ 3,761,000
Total commercial real estate | Investment properties
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | Contract	2	4	6	6
Recorded Investment	$ 387,000	$ 385,000	$ 29,056,000	$ 1,048,000
Total commercial real estate | 1-4 family properties
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | Contract	5	4	15	14
Recorded Investment	$ 188,000	$ 766,000	$ 1,972,000	$ 2,072,000
Total commercial real estate | Land and development
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | Contract	1	1	3	3
Recorded Investment	$ 40,000	$ 473,000	$ 581,000	$ 641,000
Total consumer
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | Contract	23	62	119	144
Recorded Investment	$ 1,771,000	$ 4,820,000	$ 10,537,000	$ 11,769,000
Total consumer | Consumer mortgages
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | Contract	3	10	19	15
Recorded Investment	$ 519,000	$ 1,126,000	$ 4,157,000	$ 2,577,000
Total consumer | Home equity lines
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | Contract	17	25	50	50
Recorded Investment	$ 1,119,000	$ 1,999,000	$ 3,456,000	$ 4,426,000
Total consumer | Other consumer loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | Contract	3	27	50	79
Recorded Investment	$ 133,000	$ 1,695,000	$ 2,924,000	$ 4,766,000
Below Market Interest Rate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Recorded Investment	6,511,000	8,868,000	45,185,000	19,416,000
Below Market Interest Rate | Total commercial and industrial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Recorded Investment	5,088,000	5,399,000	12,135,000	10,557,000
Below Market Interest Rate | Total commercial and industrial | Commercial, financial and agricultural
Financing Receivable, Troubled Debt Restructuring [Line Items]
Recorded Investment	3,335,000	2,577,000	8,562,000	5,703,000
Below Market Interest Rate | Total commercial and industrial | Owner-occupied
Financing Receivable, Troubled Debt Restructuring [Line Items]
Recorded Investment	1,753,000	2,822,000	3,573,000	4,854,000
Below Market Interest Rate | Total commercial real estate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Recorded Investment	408,000	1,624,000	30,411,000	3,761,000
Below Market Interest Rate | Total commercial real estate | Investment properties
Financing Receivable, Troubled Debt Restructuring [Line Items]
Recorded Investment	294,000	385,000	28,963,000	1,048,000
Below Market Interest Rate | Total commercial real estate | 1-4 family properties
Financing Receivable, Troubled Debt Restructuring [Line Items]
Recorded Investment	74,000	766,000	867,000	2,072,000
Below Market Interest Rate | Total commercial real estate | Land and development
Financing Receivable, Troubled Debt Restructuring [Line Items]
Recorded Investment	40,000	473,000	581,000	641,000
Below Market Interest Rate | Total consumer
Financing Receivable, Troubled Debt Restructuring [Line Items]
Recorded Investment	1,015,000	1,845,000	2,639,000	5,098,000
Below Market Interest Rate | Total consumer | Consumer mortgages
Financing Receivable, Troubled Debt Restructuring [Line Items]
Recorded Investment	496,000	1,008,000	1,568,000	1,245,000
Below Market Interest Rate | Total consumer | Home equity lines
Financing Receivable, Troubled Debt Restructuring [Line Items]
Recorded Investment	471,000	364,000	926,000	2,686,000
Below Market Interest Rate | Total consumer | Other consumer loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Recorded Investment	48,000	473,000	145,000	1,167,000
Other Concessions
Financing Receivable, Troubled Debt Restructuring [Line Items]
Recorded Investment	1,633,000	5,753,000	15,307,000	11,936,000
Other Concessions | Total commercial and industrial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Recorded Investment	670,000	2,778,000	6,211,000	5,265,000
Other Concessions | Total commercial and industrial | Commercial, financial and agricultural
Financing Receivable, Troubled Debt Restructuring [Line Items]
Recorded Investment	670,000	1,917,000	4,681,000	4,404,000
Other Concessions | Total commercial and industrial | Owner-occupied
Financing Receivable, Troubled Debt Restructuring [Line Items]
Recorded Investment	0	861,000	1,530,000	861,000
Other Concessions | Total commercial real estate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Recorded Investment	207,000	0	1,198,000	0
Other Concessions | Total commercial real estate | Investment properties
Financing Receivable, Troubled Debt Restructuring [Line Items]
Recorded Investment	93,000	0	93,000	0
Other Concessions | Total commercial real estate | 1-4 family properties
Financing Receivable, Troubled Debt Restructuring [Line Items]
Recorded Investment	114,000	0	1,105,000	0
Other Concessions | Total commercial real estate | Land and development
Financing Receivable, Troubled Debt Restructuring [Line Items]
Recorded Investment	0	0	0	0
Other Concessions | Total consumer
Financing Receivable, Troubled Debt Restructuring [Line Items]
Recorded Investment	756,000	2,975,000	7,898,000	6,671,000
Other Concessions | Total consumer | Consumer mortgages
Financing Receivable, Troubled Debt Restructuring [Line Items]
Recorded Investment	23,000	118,000	2,589,000	1,332,000
Other Concessions | Total consumer | Home equity lines
Financing Receivable, Troubled Debt Restructuring [Line Items]
Recorded Investment	648,000	1,635,000	2,530,000	1,740,000
Other Concessions | Total consumer | Other consumer loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Recorded Investment	$ 85,000	$ 1,222,000	$ 2,779,000	$ 3,599,000