Loans (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Summary of loans, by loan type
Total loans	$ 6,561,289	$ 6,348,172
Commercial, financial and agricultural
Summary of loans, by loan type
Total loans	3,305,124	3,322,668
Real estate - mortgage
Summary of loans, by loan type
Total loans	1,173,101	1,133,525
Commercial Real Estate:Other Construction and Land Development
Summary of loans, by loan type
Total loans	1,886,231	1,683,550
Consumer
Summary of loans, by loan type
Total loans	46,316	49,543
Foreign
Summary of loans, by loan type
Total loans	$ 150,517	$ 158,886

Amount before allowance and after deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=82891408&loc=d3e4428-111522

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5074-111524

Name:	us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant