Fair Value Measurements - Summary of Carrying Amount and Fair Values of Financial Instruments Reported on the Balance Sheets (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Balance sheet assets
Securities available for sale	$ 623,857	$ 460,797
Securities held to maturity	77,641	80,463
State tax credits held for sale	1,274	3,585
Carrying Amount
Balance sheet assets
Cash and due from banks	77,815	54,288
Federal funds sold	912	446
Interest-bearing deposits	40,507	145,048
Securities available for sale	623,857	460,797
Securities held to maturity	77,641	80,463
Other investments, at cost	26,477	14,840
Loans held for sale	4,285	9,562
Derivative financial instruments	3,577	4,016
Loans, net	3,852,971	3,114,752
State tax credits held for sale	35,247	38,071
Accrued interest receivable	11,923	11,117
Balance sheet liabilities
Deposits	3,921,251	3,233,361
Subordinated debentures and notes	118,080	105,540
Federal Home Loan Bank advances	200,992	0
Other borrowings	217,180	276,980
Derivative financial instruments	3,577	4,016
Accrued interest payable	1,459	1,105
Estimated fair value
Balance sheet assets
Cash and due from banks	77,815	54,288
Federal funds sold	912	446
Interest-bearing deposits	40,507	145,048
Securities available for sale	623,857	460,797
Securities held to maturity	77,831	79,639
Other investments, at cost	26,477	14,840
Loans held for sale	4,285	9,562
Derivative financial instruments	3,577	4,016
Loans, net	3,867,481	3,125,701
State tax credits held for sale	36,857	41,264
Accrued interest receivable	11,923	11,117
Balance sheet liabilities
Deposits	3,919,379	3,232,414
Subordinated debentures and notes	99,873	86,052
Federal Home Loan Bank advances	201,397	0
Other borrowings	217,077	276,905
Derivative financial instruments	3,577	4,016
Accrued interest payable	$ 1,459	$ 1,105