Purchased Loans - Summary of Purchased Loans (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Summary of loans
Gross loans	$ 7,451,394	$ 6,205,118
Unearned income	(2,786)	(2,409)
Loans, net of unearned income	7,448,608	6,202,709
Purchased loans
Summary of loans
Gross loans	2,155,141	1,489,137
Unearned income	0	0
Loans, net of unearned income	2,155,141	1,489,137
Commercial, financial, agricultural
Summary of loans
Gross loans	1,008,935	717,490
Loans, net of unearned income	1,008,935	717,490
Commercial, financial, agricultural \| Purchased loans
Summary of loans
Gross loans	301,100	128,200
Loans, net of unearned income	301,100	128,200
Real estate – construction
Summary of loans
Gross loans	577,720	552,679
Loans, net of unearned income	577,720	552,679
Real estate – construction \| Purchased loans
Summary of loans
Gross loans	100,082	68,753
Loans, net of unearned income	100,082	68,753
Real estate – 1-4 family mortgage
Summary of loans
Gross loans	2,295,852	1,878,177
Loans, net of unearned income	2,295,852	1,878,177
Real estate – 1-4 family mortgage \| Purchased loans
Summary of loans
Gross loans	651,792	452,447
Loans, net of unearned income	651,792	452,447
Real estate – commercial mortgage
Summary of loans
Gross loans	3,390,389	2,898,895
Loans, net of unearned income	3,390,389	2,898,895
Real estate – commercial mortgage \| Purchased loans
Summary of loans
Gross loans	1,079,049	823,758
Loans, net of unearned income	1,079,049	823,758
Installment loans to individuals
Summary of loans
Gross loans	123,810	108,627
Loans, net of unearned income	175,712	155,468
Installment loans to individuals \| Purchased loans
Summary of loans
Gross loans	23,118	15,979
Loans, net of unearned income	$ 23,118	$ 15,979

Amount of deferred interest and fee income, unamortized costs incurred to originate loans and leases, unamortized loan commitments and loan syndication fees, and premiums over or discounts from face amounts of acquired loans. Excludes amounts for loans and leases covered under loss sharing agreements.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 20
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=84159169&loc=d3e10152-111534

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-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

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.7)
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-Section 50
-Paragraph 4
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Amount before allowance of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

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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.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-URI http://asc.fasb.org/extlink&oid=82891408&loc=d3e4428-111522

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