Loans and Asset Quality Information (Schedule of Analysis of Payment Status of Loans) (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019	Jun. 30, 2019
Financing Receivable, Past Due [Line Items]
Nonaccrual loans	$ 34,922	$ 24,866
Accruing Current	4,734,850	4,402,978
Loans, gross	4,776,911	4,451,525	$ 4,337,713
Unamortized net deferred loan costs (fees)	(6,848)	1,941	1,784
Total loans	4,770,063	4,453,466	4,339,497
Accruing 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, past due	3,685	17,236
Accruing 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, past due	2,654	5,683
Accruing 90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, past due	800	762
PCI Loans
Financing Receivable, Past Due [Line Items]
Nonaccrual loans	0	0
Accruing Current	8,918	11,646
Loans, gross	9,742	12,664
PCI Loans | Accruing 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, past due	11	218
PCI Loans | Accruing 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, past due	13	38
PCI Loans | Accruing 90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, past due	800	762
Commercial, financial, and agricultural
Financing Receivable, Past Due [Line Items]
Nonaccrual loans	8,239	5,518
Accruing Current	713,401	497,788
Loans, gross	723,053	504,271	471,188
Commercial, financial, and agricultural | Accruing 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, past due	1,133	752
Commercial, financial, and agricultural | Accruing 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, past due	95	0
Commercial, financial, and agricultural | Accruing 90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, past due	0	0
Real estate, commercial | Real estate – construction, land development & other land loans
Financing Receivable, Past Due [Line Items]
Nonaccrual loans	1,038	1,067
Accruing Current	643,790	529,444
Loans, gross	648,590	530,866	456,781
Real estate, commercial | Real estate – construction, land development & other land loans | Accruing 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, past due	133	37
Real estate, commercial | Real estate – construction, land development & other land loans | Accruing 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, past due	751	152
Real estate, commercial | Real estate – construction, land development & other land loans | Accruing 90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, past due	0	0
Real estate, commercial | Real estate – mortgage – commercial and other
Financing Receivable, Past Due [Line Items]
Nonaccrual loans	16,229	8,820
Accruing Current	1,940,194	1,897,573
Loans, gross	1,959,078	1,917,280	1,900,188
Real estate, commercial | Real estate – mortgage – commercial and other | Accruing 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, past due	1,055	4,257
Real estate, commercial | Real estate – mortgage – commercial and other | Accruing 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, past due	278	0
Real estate, commercial | Real estate – mortgage – commercial and other | Accruing 90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, past due	0	0
Real estate, mortgage | Real estate – mortgage – residential (1-4 family) first mortgages
Financing Receivable, Past Due [Line Items]
Nonaccrual loans	7,327	7,552
Accruing Current	1,061,983	1,076,205
Loans, gross	1,076,411	1,105,014	1,090,601
Real estate, mortgage | Real estate – mortgage – residential (1-4 family) first mortgages | Accruing 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, past due	624	10,858
Real estate, mortgage | Real estate – mortgage – residential (1-4 family) first mortgages | Accruing 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, past due	1,279	5,056
Real estate, mortgage | Real estate – mortgage – residential (1-4 family) first mortgages | Accruing 90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, past due	0	0
Real estate, mortgage | Real estate – mortgage – home equity loans / lines of credit
Financing Receivable, Past Due [Line Items]
Nonaccrual loans	1,903	1,797
Accruing Current	315,824	334,832
Loans, gross	318,618	337,922	349,355
Real estate, mortgage | Real estate – mortgage – home equity loans / lines of credit | Accruing 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, past due	593	770
Real estate, mortgage | Real estate – mortgage – home equity loans / lines of credit | Accruing 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, past due	203	300
Real estate, mortgage | Real estate – mortgage – home equity loans / lines of credit | Accruing 90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, past due	0	0
Consumer loans
Financing Receivable, Past Due [Line Items]
Nonaccrual loans	186	112
Accruing Current	50,740	55,490
Loans, gross	51,161	56,172	$ 69,600
Consumer loans | Accruing 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, past due	136	344
Consumer loans | Accruing 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, past due	35	137
Consumer loans | Accruing 90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, past due	0	0
Loans, Excluding Purchased Credit Impaired Loans | Commercial, financial, and agricultural
Financing Receivable, Past Due [Line Items]
Loans, gross	722,868	504,058
Loans, Excluding Purchased Credit Impaired Loans | Real estate, commercial | Real estate – construction, land development & other land loans
Financing Receivable, Past Due [Line Items]
Loans, gross	645,712	530,700
Loans, Excluding Purchased Credit Impaired Loans | Real estate, commercial | Real estate – mortgage – commercial and other
Financing Receivable, Past Due [Line Items]
Loans, gross	1,957,756	1,910,650
Loans, Excluding Purchased Credit Impaired Loans | Real estate, mortgage | Real estate – mortgage – residential (1-4 family) first mortgages
Financing Receivable, Past Due [Line Items]
Loans, gross	1,071,213	1,099,671
Loans, Excluding Purchased Credit Impaired Loans | Real estate, mortgage | Real estate – mortgage – home equity loans / lines of credit
Financing Receivable, Past Due [Line Items]
Loans, gross	318,523	337,699
Loans, Excluding Purchased Credit Impaired Loans | Consumer loans
Financing Receivable, Past Due [Line Items]
Loans, gross	$ 51,097	$ 56,083