Portfolio Loans - Summary of Portfolio Loans by Category (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, before unearned loan fees	$ 9,017,642	$ 7,224,935
Non-Covered Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, before unearned loan fees	9,026,780	7,241,074
Unearned loan fees, net	(9,138)	(16,139)
Loans, including unearned loan fees	9,017,642	7,224,935
Non-Covered Loans | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, before unearned loan fees	3,396,590	3,100,299
Non-Covered Loans | Commercial - investor owned
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, before unearned loan fees	2,141,143	1,589,419
Non-Covered Loans | CRE - owner occupied
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, before unearned loan fees	2,035,785	1,498,408
Non-Covered Loans | Construction and land development
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, before unearned loan fees	734,073	546,686
Non-Covered Loans | Residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, before unearned loan fees	454,052	319,179
Non-Covered Loans | Total real estate loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, before unearned loan fees	5,365,053	3,953,692
Non-Covered Loans | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, before unearned loan fees	$ 265,137	$ 187,083