Loans and Allowance for Loan Losses (Troubled Debt Restructurings) (Details)	3 Months Ended		6 Months Ended
	Jun. 30, 2017 USD ($) Contract	Jun. 30, 2016 USD ($) Contract	Jun. 30, 2017 USD ($) Contract	Jun. 30, 2016 USD ($) Contract
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	26	49	55	110
Recorded Investment	$ 3,770,000	$ 11,990,000	$ 15,377,000	$ 32,394,000
Net charge-offs	$ 0	$ 0	$ 0
Total commercial real estate
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	9	18	17	33
Recorded Investment	$ 809,000	$ 5,542,000	$ 2,737,000	$ 7,897,000
Investment properties
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	0	1	0	3
Recorded Investment	$ 0	$ 1,389,000	$ 0	$ 1,974,000
1-4 family properties
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	8	12	16	19
Recorded Investment	$ 674,000	$ 3,419,000	$ 2,602,000	$ 4,654,000
Land and development
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	1	5	1	11
Recorded Investment	$ 135,000	$ 734,000	$ 135,000	$ 1,269,000
Total commercial and industrial
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	11	17	29	51
Recorded Investment	$ 2,657,000	$ 4,626,000	$ 12,061,000	$ 22,010,000
Commercial, financial and agricultural
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	10	15	28	45
Recorded Investment	$ 2,635,000	$ 3,392,000	$ 12,039,000	$ 18,793,000
Owner-occupied
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	1	2	1	6
Recorded Investment	$ 22,000	$ 1,234,000	$ 22,000	$ 3,217,000
Total consumer
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	6	14	9	26
Recorded Investment	$ 304,000	$ 1,822,000	$ 579,000	$ 2,487,000
Home equity lines
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	0	1	0	3
Recorded Investment	$ 0	$ 28,000	$ 0	$ 224,000
Consumer mortgages
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	1	3	1	6
Recorded Investment	$ 9,000	$ 251,000	$ 9,000	$ 405,000
Credit cards
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	0	0	0	0
Recorded Investment	$ 0	$ 0	$ 0	$ 0
Other consumer loans
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	5	10	8	17
Recorded Investment	$ 295,000	$ 1,543,000	$ 570,000	$ 1,858,000
Principal Forgiveness
Financing Receivable, Modifications [Line Items]
Recorded Investment	0	0	0	0
Principal Forgiveness | Total commercial real estate
Financing Receivable, Modifications [Line Items]
Recorded Investment	0	0	0	0
Principal Forgiveness | Investment properties
Financing Receivable, Modifications [Line Items]
Recorded Investment	0	0	0	0
Principal Forgiveness | 1-4 family properties
Financing Receivable, Modifications [Line Items]
Recorded Investment	0	0	0	0
Principal Forgiveness | Land and development
Financing Receivable, Modifications [Line Items]
Recorded Investment	0	0	0	0
Principal Forgiveness | Total commercial and industrial
Financing Receivable, Modifications [Line Items]
Recorded Investment	0	0	0	0
Principal Forgiveness | Commercial, financial and agricultural
Financing Receivable, Modifications [Line Items]
Recorded Investment	0	0	0	0
Principal Forgiveness | Owner-occupied
Financing Receivable, Modifications [Line Items]
Recorded Investment	0	0	0	0
Principal Forgiveness | Total consumer
Financing Receivable, Modifications [Line Items]
Recorded Investment	0	0	0	0
Principal Forgiveness | Home equity lines
Financing Receivable, Modifications [Line Items]
Recorded Investment	0	0	0	0
Principal Forgiveness | Consumer mortgages
Financing Receivable, Modifications [Line Items]
Recorded Investment	0	0	0	0
Principal Forgiveness | Credit cards
Financing Receivable, Modifications [Line Items]
Recorded Investment	0	0	0	0
Principal Forgiveness | Other consumer loans
Financing Receivable, Modifications [Line Items]
Recorded Investment	0	0	0	0
Below Market Interest Rate
Financing Receivable, Modifications [Line Items]
Recorded Investment	2,373,000	7,872,000	7,849,000	22,833,000
Below Market Interest Rate | Total commercial real estate
Financing Receivable, Modifications [Line Items]
Recorded Investment	478,000	4,484,000	2,089,000	5,316,000
Below Market Interest Rate | Investment properties
Financing Receivable, Modifications [Line Items]
Recorded Investment	0	1,389,000	0	1,826,000
Below Market Interest Rate | 1-4 family properties
Financing Receivable, Modifications [Line Items]
Recorded Investment	478,000	3,095,000	2,089,000	3,490,000
Below Market Interest Rate | Land and development
Financing Receivable, Modifications [Line Items]
Recorded Investment	0	0	0	0
Below Market Interest Rate | Total commercial and industrial
Financing Receivable, Modifications [Line Items]
Recorded Investment	1,895,000	3,066,000	5,760,000	16,615,000
Below Market Interest Rate | Commercial, financial and agricultural
Financing Receivable, Modifications [Line Items]
Recorded Investment	1,895,000	1,934,000	5,760,000	13,948,000
Below Market Interest Rate | Owner-occupied
Financing Receivable, Modifications [Line Items]
Recorded Investment	0	1,132,000	0	2,667,000
Below Market Interest Rate | Total consumer
Financing Receivable, Modifications [Line Items]
Recorded Investment	0	322,000	0	902,000
Below Market Interest Rate | Home equity lines
Financing Receivable, Modifications [Line Items]
Recorded Investment	0	28,000	0	224,000
Below Market Interest Rate | Consumer mortgages
Financing Receivable, Modifications [Line Items]
Recorded Investment	0	200,000	0	354,000
Below Market Interest Rate | Credit cards
Financing Receivable, Modifications [Line Items]
Recorded Investment	0	0	0	0
Below Market Interest Rate | Other consumer loans
Financing Receivable, Modifications [Line Items]
Recorded Investment	0	94,000	0	324,000
Term Extensions and/or Other Concessions
Financing Receivable, Modifications [Line Items]
Recorded Investment	1,397,000	4,118,000	7,528,000	9,561,000
Term Extensions and/or Other Concessions | Total commercial real estate
Financing Receivable, Modifications [Line Items]
Recorded Investment	331,000	1,058,000	648,000	2,581,000
Term Extensions and/or Other Concessions | Investment properties
Financing Receivable, Modifications [Line Items]
Recorded Investment	0	0	0	148,000
Term Extensions and/or Other Concessions | 1-4 family properties
Financing Receivable, Modifications [Line Items]
Recorded Investment	196,000	324,000	513,000	1,164,000
Term Extensions and/or Other Concessions | Land and development
Financing Receivable, Modifications [Line Items]
Recorded Investment	135,000	734,000	135,000	1,269,000
Term Extensions and/or Other Concessions | Total commercial and industrial
Financing Receivable, Modifications [Line Items]
Recorded Investment	762,000	1,560,000	6,301,000	5,395,000
Term Extensions and/or Other Concessions | Commercial, financial and agricultural
Financing Receivable, Modifications [Line Items]
Recorded Investment	740,000	1,458,000	6,279,000	4,845,000
Term Extensions and/or Other Concessions | Owner-occupied
Financing Receivable, Modifications [Line Items]
Recorded Investment	22,000	102,000	22,000	550,000
Term Extensions and/or Other Concessions | Total consumer
Financing Receivable, Modifications [Line Items]
Recorded Investment	304,000	1,500,000	579,000	1,585,000
Term Extensions and/or Other Concessions | Home equity lines
Financing Receivable, Modifications [Line Items]
Recorded Investment	0	0	0	0
Term Extensions and/or Other Concessions | Consumer mortgages
Financing Receivable, Modifications [Line Items]
Recorded Investment	9,000	51,000	9,000	51,000
Term Extensions and/or Other Concessions | Credit cards
Financing Receivable, Modifications [Line Items]
Recorded Investment	0	0	0	0
Term Extensions and/or Other Concessions | Other consumer loans
Financing Receivable, Modifications [Line Items]
Recorded Investment	$ 295,000	$ 1,449,000	$ 570,000	$ 1,534,000