Allowance for Credit Losses (Portfolio Credit Quality) (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Loan portfolio by credit quality indicator
2021	$ 836,952	$ 3,601,680
2020	3,010,552	1,627,511
2019	1,533,431	1,087,031
2018	999,919	556,923
2017	495,275	327,336
Prior	586,229	341,273
Total loans	7,462,358	7,541,754
Commercial, financial and agricultural
Loan portfolio by credit quality indicator
Total loans	4,680,883	4,516,288
Commercial, financial and agricultural \| Domestic \| Commercial Loan [Member]
Loan portfolio by credit quality indicator
2021	311,973	1,288,332
2020	974,852	241,724
2019	216,152	146,051
2018	140,849	85,596
2017	77,562	14,216
Prior	19,218	10,017
Total loans	1,740,606	1,785,936
Commercial, financial and agricultural \| Domestic \| Commercial Loan [Member] \| Pass [Member]
Loan portfolio by credit quality indicator
2021	307,767	1,168,671
2020	862,330	240,869
2019	215,227	145,670
2018	140,577	85,434
2017	77,456	13,901
Prior	18,898	10,000
Total loans	1,622,255	1,664,545
Commercial, financial and agricultural \| Domestic \| Commercial Loan [Member] \| Special Mention [Member]
Loan portfolio by credit quality indicator
2021	1,179	75,638
2020	74,698
Total loans	75,877	75,638
Commercial, financial and agricultural \| Domestic \| Commercial Loan [Member] \| Special Pass [Member]
Loan portfolio by credit quality indicator
2021		39,886
2020	37,037	11
2018		3
2017	3
Prior	14	17
Total loans	37,054	39,917
Commercial, financial and agricultural \| Domestic \| Commercial Loan [Member] \| Substandard [Member]
Loan portfolio by credit quality indicator
2021	3,027	3,360
2020	310	683
2019	920	289
2018	108
2017		315
Total loans	4,365	4,647
Commercial, financial and agricultural \| Domestic \| Commercial Loan [Member] \| Watch List - Doubtful
Loan portfolio by credit quality indicator
2021		777
2020	477	161
2019	5	92
2018	164	159
2017	103
Prior	306
Total loans	1,055	1,189
Commercial, financial and agricultural \| Domestic \| Commercial Real Estate Farmland and Commercial Receivable [Member]
Loan portfolio by credit quality indicator
2021	241,123	1,002,557
2020	876,622	380,123
2019	361,646	391,303
2018	462,703	192,165
2017	178,708	206,193
Prior	300,490	116,967
Total loans	2,421,292	2,289,308
Commercial, financial and agricultural \| Domestic \| Commercial Real Estate Farmland and Commercial Receivable [Member] \| Pass [Member]
Loan portfolio by credit quality indicator
2021	221,824	884,070
2020	776,277	373,993
2019	355,776	386,268
2018	457,828	189,639
2017	176,206	202,500
Prior	296,816	116,729
Total loans	2,284,727	2,153,199
Commercial, financial and agricultural \| Domestic \| Commercial Real Estate Farmland and Commercial Receivable [Member] \| Special Mention [Member]
Loan portfolio by credit quality indicator
2021	2,070	3,041
2020	1,357
2019	931	4,758
2018	4,598	177
2017	161	3,218
Prior	3,203
Total loans	12,320	11,194
Commercial, financial and agricultural \| Domestic \| Commercial Real Estate Farmland and Commercial Receivable [Member] \| Special Pass [Member]
Loan portfolio by credit quality indicator
2021	17,229	61,637
2020	44,351	942
2019		277
2018	277	80
2017	96
Total loans	61,953	62,936
Commercial, financial and agricultural \| Domestic \| Commercial Real Estate Farmland and Commercial Receivable [Member] \| Substandard [Member]
Loan portfolio by credit quality indicator
2021		53,809
2020	54,409	4,986
2019	4,745
2018		2,269
2017	2,245	475
Prior	471	1
Total loans	61,870	61,540
Commercial, financial and agricultural \| Domestic \| Commercial Real Estate Farmland and Commercial Receivable [Member] \| Watch List - Doubtful
Loan portfolio by credit quality indicator
2020	228	202
2019	194
Prior		237
Total loans	422	439
Commercial, financial and agricultural \| Domestic \| Commercial Real Estate Multifamily Receivable [Member]
Loan portfolio by credit quality indicator
2021	17,769	74,711
2020	96,173	208,356
2019	216,507	82,818
2018	115,126	64,110
2017	63,659	6,801
Prior	9,751	4,248
Total loans	518,985	441,044
Commercial, financial and agricultural \| Domestic \| Commercial Real Estate Multifamily Receivable [Member] \| Pass [Member]
Loan portfolio by credit quality indicator
2021	17,769	74,577
2020	96,046	208,356
2019	216,507	82,818
2018	115,126	64,110
2017	63,659	6,801
Prior	9,751	4,248
Total loans	518,858	440,910
Commercial, financial and agricultural \| Domestic \| Commercial Real Estate Multifamily Receivable [Member] \| Watch List - Doubtful
Loan portfolio by credit quality indicator
2021		134
2020	127
Total loans	127	134
Real estate - construction
Loan portfolio by credit quality indicator
Total loans	1,653,418	1,846,757
Real estate - construction \| Domestic \| Commercial Real Estate: other construction and land development
Loan portfolio by credit quality indicator
2021	170,443	833,796
2020	697,177	600,602
2019	548,745	320,308
2018	157,522	78,174
2017	67,581	10,534
Prior	11,950	3,343
Total loans	1,653,418	1,846,757
Real estate - construction \| Domestic \| Commercial Real Estate: other construction and land development \| Pass [Member]
Loan portfolio by credit quality indicator
2021	140,264	773,165
2020	673,184	576,707
2019	548,745	320,308
2018	157,473	78,174
2017	67,581	10,534
Prior	11,950	3,343
Total loans	1,599,197	1,762,231
Real estate - construction \| Domestic \| Commercial Real Estate: other construction and land development \| Special Mention [Member]
Loan portfolio by credit quality indicator
2021	30,179	20,828
2020		21,650
Total loans	30,179	42,478
Real estate - construction \| Domestic \| Commercial Real Estate: other construction and land development \| Special Pass [Member]
Loan portfolio by credit quality indicator
2021		23,101
2020	23,101	1,451
2018	49
Total loans	23,150	24,552
Real estate - construction \| Domestic \| Commercial Real Estate: other construction and land development \| Watch List - Doubtful
Loan portfolio by credit quality indicator
2021		16,702
2020	892	794
Total loans	892	17,496
Real estate - mortgage
Loan portfolio by credit quality indicator
Total loans	950,782	999,144
Real estate - mortgage \| Domestic \| Residential First Mortgage Financing Receivable [Member]
Loan portfolio by credit quality indicator
2021	41,581	81,090
2020	74,045	62,179
2019	76,843	72,430
2018	61,176	54,593
2017	37,745	29,299
Prior	110,307	105,528
Total loans	401,697	405,119
Real estate - mortgage \| Domestic \| Residential First Mortgage Financing Receivable [Member] \| Pass [Member]
Loan portfolio by credit quality indicator
2021	41,581	81,004
2020	73,963	62,165
2019	76,843	72,299
2018	61,176	54,593
2017	37,745	29,250
Prior	110,193	105,463
Total loans	401,501	404,774
Real estate - mortgage \| Domestic \| Residential First Mortgage Financing Receivable [Member] \| Special Pass [Member]
Loan portfolio by credit quality indicator
2020		14
2019		131
Total loans		145
Real estate - mortgage \| Domestic \| Residential First Mortgage Financing Receivable [Member] \| Substandard [Member]
Loan portfolio by credit quality indicator
2017		49
Prior	49
Total loans	49	49
Real estate - mortgage \| Domestic \| Residential First Mortgage Financing Receivable [Member] \| Watch List - Doubtful
Loan portfolio by credit quality indicator
2021		86
2020	82
Prior	65	65
Total loans	147	151
Real estate - mortgage \| Domestic \| Residential Junior Lien
Loan portfolio by credit quality indicator
2021	28,850	197,048
2020	182,697	108,276
2019	96,296	61,674
2018	51,261	75,868
2017	64,054	56,705
Prior	125,927	94,454
Total loans	549,085	594,025
Real estate - mortgage \| Domestic \| Residential Junior Lien \| Pass [Member]
Loan portfolio by credit quality indicator
2021	28,850	196,308
2020	181,957	108,276
2019	96,296	61,636
2018	51,223	75,056
2017	63,242	56,705
Prior	125,927	94,454
Total loans	547,495	592,435
Real estate - mortgage \| Domestic \| Residential Junior Lien \| Special Mention [Member]
Loan portfolio by credit quality indicator
2021		740
2020	740
2018		812
2017	812
Total loans	1,552	1,552
Real estate - mortgage \| Domestic \| Residential Junior Lien \| Watch List - Doubtful
Loan portfolio by credit quality indicator
2019		38
2018	38
Total loans	38	38
Consumer
Loan portfolio by credit quality indicator
Total loans	39,743	40,595
Consumer \| Domestic
Loan portfolio by credit quality indicator
2021	8,044	30,910
2020	24,735	7,159
2019	4,683	875
2018	598	225
2017	156	55
Prior	1,527	1,371
Total loans	39,743	40,595
Consumer \| Domestic \| Pass [Member]
Loan portfolio by credit quality indicator
2021	8,044	30,910
2020	24,735	7,159
2019	4,683	875
2018	598	225
2017	156	55
Prior	1,527	1,371
Total loans	39,743	40,595
Foreign
Loan portfolio by credit quality indicator
Total loans	137,532	138,970
Foreign \| Foreign
Loan portfolio by credit quality indicator
2021	17,169	93,236
2020	84,251	19,092
2019	12,559	11,572
2018	10,684	6,192
2017	5,810	3,533
Prior	7,059	5,345
Total loans	137,532	138,970
Foreign \| Foreign \| Pass [Member]
Loan portfolio by credit quality indicator
2021	17,169	93,236
2020	84,251	19,092
2019	12,559	11,572
2018	10,684	6,192
2017	5,810	3,533
Prior	7,059	5,345
Total loans	$ 137,532	$ 138,970

Amount of financing receivable originated more than five years prior to current fiscal year.

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Amount of financing receivable originated four years prior to current fiscal year.

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Amount of financing receivable originated in current fiscal year.

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Amount of financing receivable originated in fiscal year prior to current fiscal year.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
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Amount of financing receivable originated three years prior to current fiscal year.

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Amount of financing receivable originated two years prior to current fiscal year.

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Amount, before allowance for credit loss, of financing receivable.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 55
-Paragraph 79
-URI http://asc.fasb.org/extlink&oid=121647567&loc=SL82922352-210448

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