Loans - Summary of Allowance for Loan Losses by Portfolio Class and Category (Details) - Portfolio loans, net - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
	Dec. 31, 2019	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Allowance for Loan Losses [Roll Forward]
Balance at December 31, 2020		$ 131,527	$ 92,187	$ 136,671	$ 43,288
Financing Receivable, Allowance for Credit Loss, Period Increase (Decrease)	$ 28,387
Provision for credit losses	(1,680)
Provision for Loan, Lease, and Other Losses		(2,473)	18,391	(1,970)	40,086
Charge-offs		(1,832)	(3,664)	(8,306)	(3,968)
Recoveries		963	3,356	1,790	4,157
Balance	43,288	128,185	110,270	128,185	110,270
Commercial and industrial
Allowance for Loan Losses [Roll Forward]
Balance at December 31, 2020		55,941	45,981	58,812	27,455
Financing Receivable, Allowance for Credit Loss, Period Increase (Decrease)	6,494
Provision for credit losses	0
Provision for Loan, Lease, and Other Losses		(1,839)	7,168	(1,298)	18,759
Charge-offs		(1,451)	(3,303)	(5,190)	(3,366)
Recoveries		700	293	1,027	797
Balance	27,455	53,351	50,139	53,351	50,139
CRE - investor owned
Allowance for Loan Losses [Roll Forward]
Balance at December 31, 2020		33,105	19,892	32,062	5,935
Financing Receivable, Allowance for Credit Loss, Period Increase (Decrease)	10,726
Provision for credit losses	(5)
Provision for Loan, Lease, and Other Losses		2,859	2,599	6,240	5,823
Charge-offs		0	(224)	(2,372)	(226)
Recoveries		39	2,752	73	2,766
Balance	5,935	36,003	25,019	36,003	25,019
CRE - owner occupied
Allowance for Loan Losses [Roll Forward]
Balance at December 31, 2020		20,219	9,477	17,012	4,873
Financing Receivable, Allowance for Credit Loss, Period Increase (Decrease)	2,598
Provision for credit losses	(57)
Provision for Loan, Lease, and Other Losses		(4,449)	1,600	(1,223)	3,594
Charge-offs		(216)	0	(244)	0
Recoveries		10	11	19	80
Balance	4,873	15,564	11,088	15,564	11,088
Construction and land development
Allowance for Loan Losses [Roll Forward]
Balance at December 31, 2020		14,557	9,895	21,413	2,611
Financing Receivable, Allowance for Credit Loss, Period Increase (Decrease)	5,183
Provision for credit losses	(217)
Provision for Loan, Lease, and Other Losses		(2,957)	6,038	(10,048)	8,347
Charge-offs		0	0	0	(31)
Recoveries		32	29	267	69
Balance	2,611	11,632	15,962	11,632	15,962
Residential real estate
Allowance for Loan Losses [Roll Forward]
Balance at December 31, 2020		4,305	5,395	4,585	1,280
Financing Receivable, Allowance for Credit Loss, Period Increase (Decrease)	3,470
Provision for credit losses	(1,401)
Provision for Loan, Lease, and Other Losses		255	744	103	2,755
Charge-offs		(44)	(32)	(315)	(154)
Recoveries		161	226	304	383
Balance	1,280	4,677	6,333	4,677	6,333
Other
Allowance for Loan Losses [Roll Forward]
Balance at December 31, 2020		3,400	1,547	2,787	1,134
Financing Receivable, Allowance for Credit Loss, Period Increase (Decrease)	(84)
Provision for credit losses	0
Provision for Loan, Lease, and Other Losses		3,658	242	4,256	808
Charge-offs		(121)	(105)	(185)	(191)
Recoveries		21	45	100	62
Balance	$ 1,134	$ 6,958	$ 1,729	$ 6,958	$ 1,729