Loans - Components of Purchased Loans (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	$ 453,686	$ 332,458
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net	453,686	332,321
Construction and land development [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	22,636	11,159
Commercial Real Estate [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	315,677	232,503
Residential Real Estate [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	52,497	45,654
Commercial and Financial [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	61,858	40,503
Consumer Loan [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	1,018	2,639
Purchased Credit Impaired [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	12,996	12,109
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net	12,996	12,109
Purchased Credit Impaired [Member] | Construction and land development [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	114	114
Purchased Credit Impaired [Member] | Commercial Real Estate [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	11,257	9,990
Purchased Credit Impaired [Member] | Residential Real Estate [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	684	922
Purchased Credit Impaired [Member] | Commercial and Financial [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	941	1,083
Purchased Credit Impaired [Member] | Consumer Loan [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	0	0
Purchased Unimpaired Loans [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	440,690	320,349
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net	440,690	320,212
Purchased Unimpaired Loans [Member] | Construction and land development [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	22,522	11,045
Purchased Unimpaired Loans [Member] | Commercial Real Estate [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	304,420	222,513
Purchased Unimpaired Loans [Member] | Residential Real Estate [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	51,813	44,732
Purchased Unimpaired Loans [Member] | Commercial and Financial [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	60,917	39,420
Purchased Unimpaired Loans [Member] | Consumer Loan [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	$ 1,018	$ 2,639