Loans - Summary of Recorded Investment in Portfolio Loans by Class and Category Based on Impairment Method (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2020 USD ($) loan	Jun. 30, 2019 USD ($) loan	Mar. 31, 2020 USD ($)	Jan. 01, 2020 USD ($)	Dec. 31, 2019 USD ($)
Summary of Recorded Investment in Non-covered Loans by Portfolio Class and Category Based on Impairment Method [Line Items]
Total				$ 43,288
Portfolio loans, net
Summary of Recorded Investment in Non-covered Loans by Portfolio Class and Category Based on Impairment Method [Line Items]
Financing Receivable, Modifications, Number of Contracts | loan	3	3
Financing Receivable, Troubled Debt Restructuring, Postmodification	$ 3,886	$ 520
Financing Receivable, Troubled Debt Restructuring, Premodification	3,886	$ 520
Total	110,270		$ 92,187	69,995	$ 43,288
Loans - Ending balance:
Unamortized Loan Commitment and Origination Fees and Unamortized Discounts or Premiums	(24,441)				(2,616)
Total	$ 6,164,492				5,316,953
Portfolio loans, net | Commercial and industrial
Summary of Recorded Investment in Non-covered Loans by Portfolio Class and Category Based on Impairment Method [Line Items]
Financing Receivable, Modifications, Number of Contracts | loan	1	0
Financing Receivable, Troubled Debt Restructuring, Postmodification	$ 3,731	$ 0
Financing Receivable, Troubled Debt Restructuring, Premodification	3,731	$ 0
Total	50,139		45,981	33,949	27,455
Loans - Ending balance:
Total	3,165,611				2,361,157
Portfolio loans, net | CRE - investor owned
Summary of Recorded Investment in Non-covered Loans by Portfolio Class and Category Based on Impairment Method [Line Items]
Total	25,019		19,892	16,656	5,935
Loans - Ending balance:
Total	$ 1,309,895				1,299,884
Portfolio loans, net | CRE - owner occupied
Summary of Recorded Investment in Non-covered Loans by Portfolio Class and Category Based on Impairment Method [Line Items]
Financing Receivable, Modifications, Number of Contracts | loan	0	1
Financing Receivable, Troubled Debt Restructuring, Postmodification	$ 0	$ 188
Financing Receivable, Troubled Debt Restructuring, Premodification	0	$ 188
Total	11,088		9,477	7,414	4,873
Loans - Ending balance:
Total	738,549				697,437
Portfolio loans, net | Construction and land development
Summary of Recorded Investment in Non-covered Loans by Portfolio Class and Category Based on Impairment Method [Line Items]
Total	15,962		9,895	7,577	2,611
Loans - Ending balance:
Total	$ 481,221				457,273
Portfolio loans, net | Residential real estate
Summary of Recorded Investment in Non-covered Loans by Portfolio Class and Category Based on Impairment Method [Line Items]
Financing Receivable, Modifications, Number of Contracts | loan	2	2
Financing Receivable, Troubled Debt Restructuring, Postmodification	$ 155	$ 332
Financing Receivable, Troubled Debt Restructuring, Premodification	155	$ 332
Total	6,333		5,395	3,349	1,280
Loans - Ending balance:
Total	326,992				366,261
Portfolio loans, net | Other
Summary of Recorded Investment in Non-covered Loans by Portfolio Class and Category Based on Impairment Method [Line Items]
Total	1,729		$ 1,547	$ 1,050	1,134
Loans - Ending balance:
Total	$ 142,224				$ 134,941