Acquired Loans - Aging Analysis of Past Due and Nonaccrual Acquired Loans, by Class (Details) - USD ($) $ in Thousands		Sep. 30, 2017	Dec. 31, 2016
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due		$ 8,700	$ 8,673
Nonaccrual	[1]	314	631
Current		274,743	262,943
Acquired Loans		283,757	272,247
Past Due 30 to 59 Days [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due		4,215	4,354
Past Due 60 to 89 Days [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due		504	589
Past Due 90 Days or More [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due	[2]	3,981	3,730
Construction, Land Development and Other Land [Member] | Loans Secured by Real Estate [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due		3,849	1,242
Nonaccrual	[1]	0	0
Current		25,535	19,608
Acquired Loans		29,384	20,850
Construction, Land Development and Other Land [Member] | Loans Secured by Real Estate [Member] | Past Due 30 to 59 Days [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due		1,946	321
Construction, Land Development and Other Land [Member] | Loans Secured by Real Estate [Member] | Past Due 60 to 89 Days [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due		23	100
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]	1,880	821
Secured by 1-4 Family Residential Properties [Member] | Loans Secured by Real Estate [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due		2,354	2,964
Nonaccrual	[1]	314	41
Current		63,078	66,535
Acquired Loans		65,746	69,540
Secured by 1-4 Family Residential Properties [Member] | Loans Secured by Real Estate [Member] | Past Due 30 to 59 Days [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due		1,050	1,495
Secured by 1-4 Family Residential Properties [Member] | Loans Secured by Real Estate [Member] | Past Due 60 to 89 Days [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due		481	412
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]	823	1,057
Secured by Nonfarm, Nonresidential Properties [Member] | Loans Secured by Real Estate [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due		1,447	2,039
Nonaccrual	[1]	0	328
Current		120,753	101,453
Acquired Loans		122,200	103,820
Secured by Nonfarm, Nonresidential Properties [Member] | Loans Secured by Real Estate [Member] | Past Due 30 to 59 Days [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due		442	1,658
Secured by Nonfarm, Nonresidential Properties [Member] | Loans Secured by Real Estate [Member] | Past Due 60 to 89 Days [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due		0	38
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]	1,005	343
Other Real Estate Secured [Member] | Loans Secured by Real Estate [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due		275	2,214
Nonaccrual	[1]	0	0
Current		18,156	16,796
Acquired Loans		18,431	19,010
Other Real Estate Secured [Member] | Loans Secured by Real Estate [Member] | Past Due 30 to 59 Days [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due		4	769
Other Real Estate Secured [Member] | Loans Secured by Real Estate [Member] | Past Due 60 to 89 Days [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due		0	0
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]	271	1,445
Commercial and Industrial Loans [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due		740	99
Nonaccrual	[1]	0	262
Current		33,384	36,535
Acquired Loans		34,124	36,896
Commercial and Industrial Loans [Member] | Past Due 30 to 59 Days [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due		740	60
Commercial and Industrial Loans [Member] | Past Due 60 to 89 Days [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due		0	39
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]
Acquired Loans, Past Due		35	115
Nonaccrual	[1]	0	0
Current		2,714	3,250
Acquired Loans		2,749	3,365
Consumer Loans [Member] | Past Due 30 to 59 Days [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due		33	51
Consumer Loans [Member] | Past Due 60 to 89 Days [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due		0	0
Consumer Loans [Member] | Past Due 90 Days or More [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due	[2]	2	64
Other Loans [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due		0	0
Nonaccrual	[1]	0	0
Current		11,123	18,766
Acquired Loans		11,123	18,766
Other Loans [Member] | Past Due 30 to 59 Days [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due		0	0
Other Loans [Member] | Past Due 60 to 89 Days [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due		0	0
Other Loans [Member] | Past Due 90 Days or More [Member]
Acquired Loans, Aging [Abstract]
Acquired Loans, Past Due	[2]	$ 0	$ 0

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

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