Loans - Schedule of Portfolio Loans, Purchased Credit Impaired Loans and Purchased Unimpaired Loans (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	$ 4,888,139	$ 4,825,214
Deferred costs	18,200	16,900
Construction and land development
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	379,991	443,568
Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	2,190,285	2,132,066
Residential real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	1,400,184	1,324,377
Commercial and financial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	701,747	722,322
Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	215,932	202,881
Portfolio Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	3,817,358	3,588,251
Portfolio Loans | Construction and land development
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	300,182	301,473
Portfolio Loans | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	1,552,024	1,437,989
Portfolio Loans | Residential real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	1,153,951	1,055,525
Portfolio Loans | Commercial and financial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	605,237	603,057
Portfolio Loans | Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	205,964	190,207
PCI Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	13,581	14,434
PCI Loans | Construction and land development
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	155	151
PCI Loans | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	10,324	10,828
PCI Loans | Residential real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	2,468	2,718
PCI Loans | Commercial and financial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	634	737
PCI Loans | Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	0	0
PULs
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	1,057,200	1,222,529
PULs | Construction and land development
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	79,654	141,944
PULs | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	627,937	683,249
PULs | Residential real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	243,765	266,134
PULs | Commercial and financial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	95,876	118,528
PULs | Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	$ 9,968	$ 12,674