Revenue Recognition - Summary of Company's Revenue Streams (Details) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Noninterest income:
Loan servicing fees	$ 481	$ 434	$ 546	$ 1,395	$ 1,353
Earnings on bank-owned life insurance	2,270	1,314	861	4,920	2,622
Net gain (loss) from sales of loans	9,542	(2,032)	2,313	8,281	4,944
Net gain (loss) from sales of investment securities	1,141	(21)	4,261	8,880	4,900
Other income	3,340	2,653	1,228	7,747	3,689
Total noninterest income	26,758	6,898	11,430	48,131	25,435
Service charges on deposit accounts
Noninterest income:
Noninterest income	1,593	1,399	1,440	4,707	4,211
Other service fee income
Noninterest income:
Noninterest income	487	297	360	1,095	1,079
Debit card interchange income
Noninterest income:
Noninterest income	944	457	421	1,749	2,637
Custodial account fees
Noninterest income:
Noninterest income	6,960	2,397	0	9,357	0
Within Scope
Noninterest income:
Other income	1,233	184	592	1,634	1,328
Total noninterest income	11,217	4,734	2,813	18,542	9,255
Within Scope | Service charges on deposit accounts
Noninterest income:
Noninterest income	1,593	1,399	1,440	4,707	4,211
Within Scope | Other service fee income
Noninterest income:
Noninterest income	487	297	360	1,095	1,079
Within Scope | Debit card interchange income
Noninterest income:
Noninterest income	944	457	421	1,749	2,637
Within Scope | Custodial account fees
Noninterest income:
Noninterest income	6,960	2,397	0	9,357	0
Out of Scope
Noninterest income:
Loan servicing fees	481	434	546	1,395	1,353
Earnings on bank-owned life insurance	2,270	1,314	861	4,920	2,622
Net gain (loss) from sales of loans	9,542	(2,032)	2,313	8,281	4,944
Net gain (loss) from sales of investment securities	1,141	(21)	4,261	8,880	4,900
Other income	2,107	2,469	636	6,113	2,361
Total noninterest income	$ 15,541	$ 2,164	$ 8,617	$ 29,589	$ 16,180