Loans - Summary of Allowance for Loan Losses by Portfolio Class and Category (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
	Jan. 01, 2020	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Allowance for Loan Losses [Roll Forward]
Balance	$ 43,288
Portfolio loans, net
Allowance for Loan Losses [Roll Forward]
Financing Receivable, Allowance for Credit Loss, Period Increase (Decrease)	28,387
Provision for Loan, Lease, and Other Losses		$ 18,391		$ 40,086
Balance at December 31, 2019	43,288	92,187		43,288
Provision for credit losses	(1,680)	18,400	$ 1,700	40,100	$ 3,200
Charge-offs		(3,664)		(3,968)
Recoveries		3,356		4,157
Balance	69,995	110,270		110,270
Portfolio loans, net | Commercial and industrial
Allowance for Loan Losses [Roll Forward]
Financing Receivable, Allowance for Credit Loss, Period Increase (Decrease)	6,494
Provision for Loan, Lease, and Other Losses		7,168		18,759
Balance at December 31, 2019	27,455	45,981		27,455
Provision for credit losses	0
Charge-offs		(3,303)		(3,366)
Recoveries		293		797
Balance	33,949	50,139		50,139
Portfolio loans, net | CRE - investor owned
Allowance for Loan Losses [Roll Forward]
Financing Receivable, Allowance for Credit Loss, Period Increase (Decrease)	10,726
Provision for Loan, Lease, and Other Losses		2,599		5,823
Balance at December 31, 2019	5,935	19,892		5,935
Provision for credit losses	(5)
Charge-offs		(224)		(226)
Recoveries		2,752		2,766
Balance	16,656	25,019		25,019
Portfolio loans, net | CRE - owner occupied
Allowance for Loan Losses [Roll Forward]
Financing Receivable, Allowance for Credit Loss, Period Increase (Decrease)	2,598
Provision for Loan, Lease, and Other Losses		1,600		3,594
Balance at December 31, 2019	4,873	9,477		4,873
Provision for credit losses	(57)
Charge-offs		0		0
Recoveries		11		80
Balance	7,414	11,088		11,088
Portfolio loans, net | Construction and land development
Allowance for Loan Losses [Roll Forward]
Financing Receivable, Allowance for Credit Loss, Period Increase (Decrease)	5,183
Provision for Loan, Lease, and Other Losses		6,038		8,347
Balance at December 31, 2019	2,611	9,895		2,611
Provision for credit losses	(217)
Charge-offs		0		(31)
Recoveries		29		69
Balance	7,577	15,962		15,962
Portfolio loans, net | Residential real estate
Allowance for Loan Losses [Roll Forward]
Financing Receivable, Allowance for Credit Loss, Period Increase (Decrease)	3,470
Provision for Loan, Lease, and Other Losses		744		2,755
Balance at December 31, 2019	1,280	5,395		1,280
Provision for credit losses	(1,401)
Charge-offs		(32)		(154)
Recoveries		226		383
Balance	3,349	6,333		6,333
Portfolio loans, net | Other
Allowance for Loan Losses [Roll Forward]
Financing Receivable, Allowance for Credit Loss, Period Increase (Decrease)	(84)
Provision for Loan, Lease, and Other Losses		242		808
Balance at December 31, 2019	1,134	1,547		1,134
Provision for credit losses	0
Charge-offs		(105)		(191)
Recoveries		45		62
Balance	$ 1,050	$ 1,729		$ 1,729