Loans and Allowance for Loan Losses - Schedule of Accounts, Notes, Loans and Financing Receivable (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Loans Receivable	$ 4,296,804	$ 4,153,982
Loans Receivable weighted average interest rate	4.29%	4.97%
SEC Schedule, 12-09, Allowance, Credit Loss
Loans Receivable	$ (55,743)	$ (40,294)
Undisbursed portion of loans in process
Loans Receivable	(863,722)	(850,666)
Deferred loan fees and gains, net
Loans Receivable	(9,260)	(7,104)
Commercial construction
Loans Receivable	1,212,837	1,322,861
Commercial Real Estate
Loans Receivable	1,553,677	1,494,172
Industrial revenue bonds
Loans Receivable	14,003	13,189
Consumer auto
Loans Receivable	86,173	151,854
Home Equity Line of Credit
Loans Receivable	114,689	118,988
Loans Receivable, Gross
Loans Receivable	5,225,529	5,052,046
Land development
Loans Receivable	54,010	40,431
One- to four-family residential construction
Loans Receivable	42,793	33,963
Subdivision construction
Loans Receivable	30,894	16,088
Owner occupied one- to four-family residential
Loans Receivable	470,436	387,016
Non-owner occupied one- to four-family residential
Loans Receivable	114,569	120,343
Other residential
Loans Receivable	1,021,145	866,006
Commercial business
Loans Receivable	370,898	313,209
Consumer other
Loans Receivable	40,762	46,720
Acquired Loans Net of Discount
Loans Receivable	$ 98,643	$ 127,206