Fair Value - Carrying Amount and Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
ASSETS
Securities available for sale	$ 675,100	$ 584,908
Carrying Amount
ASSETS
Cash and cash equivalents	737,673	532,694
Securities available for sale	675,100	584,908
Trading securities	9,960	6,649
Loans held for sale	10,528	8,514
Net loans	3,432,937	3,337,449
FHLB and other restricted interests	21,478	21,018
Interest rate swaps	2,856	4,017
Accrued interest receivable	18,119	17,659
LIABILITIES
Deposits	(4,504,765)	(4,181,744)
Subordinated notes and debentures	(154,136)	(70,620)
Interest rate swaps	(3,454)	(4,785)
Accrued interest payable	(1,200)	(1,096)
Total Fair Value
ASSETS
Cash and cash equivalents	737,673	532,694
Securities available for sale	675,100	584,908
Trading securities	9,960	6,649
Loans held for sale	10,716	8,617
Net loans	3,428,379	3,339,482
Interest rate swaps	2,856	4,017
Accrued interest receivable	18,085	17,659
LIABILITIES
Deposits	(4,512,221)	(4,193,200)
Subordinated notes and debentures	(141,611)	(62,583)
Interest rate swaps	(3,454)	(4,785)
Accrued interest payable	(1,200)	(1,096)
Quoted Prices in Active Markets for Identical Assets (Level 1) | Total Fair Value
ASSETS
Cash and cash equivalents	737,673	532,694
Securities available for sale	0	16,018
Trading securities	9,960	6,599
Loans held for sale	0	0
Net loans	0	0
Interest rate swaps	0	0
Accrued interest receivable	0	61
LIABILITIES
Deposits	(4,060,507)	(3,705,200)
Subordinated notes and debentures	0	0
Interest rate swaps	0	0
Accrued interest payable	0	0
Significant Other Observable Inputs (Level 2) | Total Fair Value
ASSETS
Cash and cash equivalents	0	0
Securities available for sale	665,274	568,826
Trading securities	0	50
Loans held for sale	10,716	8,617
Net loans	0	0
Interest rate swaps	2,856	4,017
Accrued interest receivable	2,293	2,152
LIABILITIES
Deposits	(451,714)	(488,000)
Subordinated notes and debentures	(141,611)	(62,583)
Interest rate swaps	(3,454)	(4,785)
Accrued interest payable	(1,200)	(1,096)
Significant Unobservable Inputs (Level 3) | Total Fair Value
ASSETS
Cash and cash equivalents	0	0
Securities available for sale	9,826	64
Trading securities	0	0
Loans held for sale	0	0
Net loans	3,428,379	3,339,482
Interest rate swaps	0	0
Accrued interest receivable	15,792	15,446
LIABILITIES
Deposits	0	0
Subordinated notes and debentures	0	0
Interest rate swaps	0	0
Accrued interest payable	$ 0	$ 0