Acquired Loans - Acquired Loans by Loan Type and Credit Quality Indicator (Details) - USD ($) $ in Thousands		Sep. 30, 2019	Dec. 31, 2018
Acquired Loans, Commercial Loans [Abstract]
Acquired loans		$ 79,755	$ 105,701
Acquired Loans, Aging [Abstract]
Current		76,887	104,377
Acquired Loans, Past Due		4,117	2,555
Nonaccrual	[1]	0	0
Total Acquired Loans		81,004	106,932
Past Due 90 Days or More [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due	[2]	2,662	1,546
Construction, Land Development and Other Land [Member] | Loans Secured by Real Estate [Member]
Acquired Loans, Aging [Abstract]
Current		5,287	5,786
Acquired Loans, Past Due		130	92
Nonaccrual	[1]	0	0
Total Acquired Loans		5,417	5,878
Construction, Land Development and Other Land [Member] | Loans Secured by Real Estate [Member] | Past Due 90 Days or More [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due	[2]	41	87
Secured by 1-4 Family Residential Properties [Member] | Loans Secured by Real Estate [Member]
Acquired Loans, Aging [Abstract]
Current		17,456	21,303
Acquired Loans, Past Due		981	1,253
Nonaccrual	[1]	0	0
Total Acquired Loans		18,437	22,556
Secured by 1-4 Family Residential Properties [Member] | Loans Secured by Real Estate [Member] | Past Due 90 Days or More [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due	[2]	380	481
Secured by Nonfarm, Nonresidential Properties [Member] | Loans Secured by Real Estate [Member]
Acquired Loans, Aging [Abstract]
Current		39,271	46,795
Acquired Loans, Past Due		1,659	1,184
Nonaccrual	[1]	0	0
Total Acquired Loans		40,930	47,979
Secured by Nonfarm, Nonresidential Properties [Member] | Loans Secured by Real Estate [Member] | Past Due 90 Days or More [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due	[2]	910	978
Other Real Estate Secured [Member] | Loans Secured by Real Estate [Member]
Acquired Loans, Aging [Abstract]
Current		6,836	8,237
Acquired Loans, Past Due		51	16
Nonaccrual	[1]	0	0
Total Acquired Loans		6,887	8,253
Other Real Estate Secured [Member] | Loans Secured by Real Estate [Member] | Past Due 90 Days or More [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due	[2]	51	0
Commercial and Industrial Loans [Member]
Acquired Loans, Aging [Abstract]
Current		4,925	15,267
Acquired Loans, Past Due		0	0
Nonaccrual	[1]	0	0
Total Acquired Loans		4,925	15,267
Commercial and Industrial Loans [Member] | Past Due 90 Days or More [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due	[2]	0	0
Consumer Loans [Member]
Acquired Loans, Aging [Abstract]
Current		577	1,346
Acquired Loans, Past Due		16	10
Nonaccrual	[1]	0	0
Total Acquired Loans		593	1,356
Consumer Loans [Member] | Past Due 90 Days or More [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due	[2]	0	0
Other Loans [Member]
Acquired Loans, Aging [Abstract]
Current		2,535	5,643
Acquired Loans, Past Due		1,280	0
Nonaccrual	[1]	0	0
Total Acquired Loans		3,815	5,643
Other Loans [Member] | Past Due 90 Days or More [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due	[2]	1,280	0
Commercial LHFI [Member] | Commercial Loan [Member]
Acquired Loans, Commercial Loans [Abstract]
Acquired loans		65,304	87,740
Commercial LHFI [Member] | Pass [Member]
Acquired Loans, Commercial Loans [Abstract]
Acquired loans		50,010	62,437
Commercial LHFI [Member] | Special Mention [Member]
Acquired Loans, Commercial Loans [Abstract]
Acquired loans		43	71
Commercial LHFI [Member] | Substandard [Member]
Acquired Loans, Commercial Loans [Abstract]
Acquired loans		13,198	22,174
Commercial LHFI [Member] | Doubtful [Member]
Acquired Loans, Commercial Loans [Abstract]
Acquired loans		2,053	3,058
Commercial LHFI [Member] | Construction, Land Development and Other Land [Member] | Loans Secured by Real Estate [Member] | Commercial Loan [Member]
Acquired Loans, Commercial Loans [Abstract]
Acquired loans		4,829	5,227
Commercial LHFI [Member] | Construction, Land Development and Other Land [Member] | Pass [Member] | Loans Secured by Real Estate [Member]
Acquired Loans, Commercial Loans [Abstract]
Acquired loans		4,633	4,923
Commercial LHFI [Member] | Construction, Land Development and Other Land [Member] | Special Mention [Member] | Loans Secured by Real Estate [Member]
Acquired Loans, Commercial Loans [Abstract]
Acquired loans			26
Commercial LHFI [Member] | Construction, Land Development and Other Land [Member] | Substandard [Member] | Loans Secured by Real Estate [Member]
Acquired Loans, Commercial Loans [Abstract]
Acquired loans		196	278
Commercial LHFI [Member] | Secured by 1-4 Family Residential Properties [Member] | Loans Secured by Real Estate [Member] | Commercial Loan [Member]
Acquired Loans, Commercial Loans [Abstract]
Acquired loans		3,918	5,371
Commercial LHFI [Member] | Secured by 1-4 Family Residential Properties [Member] | Pass [Member] | Loans Secured by Real Estate [Member]
Acquired Loans, Commercial Loans [Abstract]
Acquired loans		3,294	4,341
Commercial LHFI [Member] | Secured by 1-4 Family Residential Properties [Member] | Special Mention [Member] | Loans Secured by Real Estate [Member]
Acquired Loans, Commercial Loans [Abstract]
Acquired loans		43	45
Commercial LHFI [Member] | Secured by 1-4 Family Residential Properties [Member] | Substandard [Member] | Loans Secured by Real Estate [Member]
Acquired Loans, Commercial Loans [Abstract]
Acquired loans		581	534
Commercial LHFI [Member] | Secured by 1-4 Family Residential Properties [Member] | Doubtful [Member] | Loans Secured by Real Estate [Member]
Acquired Loans, Commercial Loans [Abstract]
Acquired loans			451
Commercial LHFI [Member] | Secured by Nonfarm, Nonresidential Properties [Member] | Loans Secured by Real Estate [Member] | Commercial Loan [Member]
Acquired Loans, Commercial Loans [Abstract]
Acquired loans		40,930	47,979
Commercial LHFI [Member] | Secured by Nonfarm, Nonresidential Properties [Member] | Pass [Member] | Loans Secured by Real Estate [Member]
Acquired Loans, Commercial Loans [Abstract]
Acquired loans		29,471	34,933
Commercial LHFI [Member] | Secured by Nonfarm, Nonresidential Properties [Member] | Substandard [Member] | Loans Secured by Real Estate [Member]
Acquired Loans, Commercial Loans [Abstract]
Acquired loans		11,062	12,614
Commercial LHFI [Member] | Secured by Nonfarm, Nonresidential Properties [Member] | Doubtful [Member] | Loans Secured by Real Estate [Member]
Acquired Loans, Commercial Loans [Abstract]
Acquired loans		397	432
Commercial LHFI [Member] | Other Real Estate Secured [Member] | Loans Secured by Real Estate [Member] | Commercial Loan [Member]
Acquired Loans, Commercial Loans [Abstract]
Acquired loans		6,887	8,253
Commercial LHFI [Member] | Other Real Estate Secured [Member] | Pass [Member] | Loans Secured by Real Estate [Member]
Acquired Loans, Commercial Loans [Abstract]
Acquired loans		6,817	7,653
Commercial LHFI [Member] | Other Real Estate Secured [Member] | Substandard [Member] | Loans Secured by Real Estate [Member]
Acquired Loans, Commercial Loans [Abstract]
Acquired loans		70	190
Commercial LHFI [Member] | Other Real Estate Secured [Member] | Doubtful [Member] | Loans Secured by Real Estate [Member]
Acquired Loans, Commercial Loans [Abstract]
Acquired loans			410
Commercial LHFI [Member] | Commercial and Industrial Loans [Member] | Commercial Loan [Member]
Acquired Loans, Commercial Loans [Abstract]
Acquired loans		4,925	15,267
Commercial LHFI [Member] | Commercial and Industrial Loans [Member] | Pass [Member]
Acquired Loans, Commercial Loans [Abstract]
Acquired loans		3,269	6,560
Commercial LHFI [Member] | Commercial and Industrial Loans [Member] | Substandard [Member]
Acquired Loans, Commercial Loans [Abstract]
Acquired loans			6,942
Commercial LHFI [Member] | Commercial and Industrial Loans [Member] | Doubtful [Member]
Acquired Loans, Commercial Loans [Abstract]
Acquired loans		1,656	1,765
Commercial LHFI [Member] | Other Loans [Member] | Commercial Loan [Member]
Acquired Loans, Commercial Loans [Abstract]
Acquired loans		3,815	5,643
Commercial LHFI [Member] | Other Loans [Member] | Pass [Member]
Acquired Loans, Commercial Loans [Abstract]
Acquired loans		2,526	4,027
Commercial LHFI [Member] | Other Loans [Member] | Substandard [Member]
Acquired Loans, Commercial Loans [Abstract]
Acquired loans		1,289	1,616
Consumer LHFI [Member]
Acquired Loans, Aging [Abstract]
Current		14,752	18,121
Subtotal		15,700	19,192
Total Acquired Loans		81,004	106,932
Consumer LHFI [Member] | Past Due 30-89 Days [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due		568	586
Consumer LHFI [Member] | Past Due 90 Days or More [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due		380	485
Consumer LHFI [Member] | Construction, Land Development and Other Land [Member] | Loans Secured by Real Estate [Member]
Acquired Loans, Aging [Abstract]
Current		527	642
Subtotal		588	651
Total Acquired Loans		5,417	5,878
Consumer LHFI [Member] | Construction, Land Development and Other Land [Member] | Loans Secured by Real Estate [Member] | Past Due 30-89 Days [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due		61	5
Consumer LHFI [Member] | Construction, Land Development and Other Land [Member] | Loans Secured by Real Estate [Member] | Past Due 90 Days or More [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due			4
Consumer LHFI [Member] | Secured by 1-4 Family Residential Properties [Member] | Loans Secured by Real Estate [Member]
Acquired Loans, Aging [Abstract]
Current		13,648	16,133
Subtotal		14,519	17,185
Total Acquired Loans		18,437	22,556
Consumer LHFI [Member] | Secured by 1-4 Family Residential Properties [Member] | Loans Secured by Real Estate [Member] | Past Due 30-89 Days [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due		491	571
Consumer LHFI [Member] | Secured by 1-4 Family Residential Properties [Member] | Loans Secured by Real Estate [Member] | Past Due 90 Days or More [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due		380	481
Consumer LHFI [Member] | Secured by Nonfarm, Nonresidential Properties [Member] | Loans Secured by Real Estate [Member]
Acquired Loans, Aging [Abstract]
Total Acquired Loans		40,930	47,979
Consumer LHFI [Member] | Other Real Estate Secured [Member] | Loans Secured by Real Estate [Member]
Acquired Loans, Aging [Abstract]
Total Acquired Loans		6,887	8,253
Consumer LHFI [Member] | Commercial and Industrial Loans [Member]
Acquired Loans, Aging [Abstract]
Total Acquired Loans		4,925	15,267
Consumer LHFI [Member] | Consumer Loans [Member]
Acquired Loans, Aging [Abstract]
Current		577	1,346
Subtotal		593	1,356
Total Acquired Loans		593	1,356
Consumer LHFI [Member] | Consumer Loans [Member] | Past Due 30-89 Days [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due		16	10
Consumer LHFI [Member] | Other Loans [Member]
Acquired Loans, Aging [Abstract]
Total Acquired Loans		$ 3,815	$ 5,643

[1] Acquired loans not accounted for under FASB ASC Topic 310-30.

[2] Past due 90 days or more but still accruing interest.