Loans - Summary of Portfolio Loans by Category (Details) - Portfolio loans, net - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, before unearned loan fees	$ 7,308,905	$ 7,241,074
Unearned loan fees, net	(20,124)	(16,139)
Loans, including unearned loan fees	7,288,781	7,224,935
Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, before unearned loan fees	3,096,319	3,100,299
Loans, including unearned loan fees	3,079,643
Commercial - investor owned
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, before unearned loan fees	1,669,215	1,589,419
Loans, including unearned loan fees	1,669,215
Commercial - owner occupied
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, before unearned loan fees	1,517,755	1,498,408
Loans, including unearned loan fees	1,517,755
Construction and land development
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, before unearned loan fees	510,501	546,686
Loans, including unearned loan fees	510,501
Residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, before unearned loan fees	303,047	319,179
Loans, including unearned loan fees	303,047
Total real estate loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, before unearned loan fees	4,000,518	3,953,692
Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, before unearned loan fees	212,068	$ 187,083
Loans, including unearned loan fees	$ 208,620

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Amount, after fee received for commitment to originate or purchase, of financing receivable. Excludes financing receivable covered under loss sharing agreement.

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Amount of deferred fees paid by borrowers and unamortized costs incurred to originate loans and leases, unamortized loan commitments and loan syndication fees, and premiums over or discounts from face amounts of loans that are being amortized into income as an adjustment to yield. Excludes amounts for loans and leases covered under loss sharing agreements.

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