Loans - Composition of Loan Portfolio (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss and fee		$ 5,140,940
Net deferred fees		(3,117)
Loans, net of deferred fees	$ 6,021,232	5,137,823
Commercial, secured by real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss and fee		3,589,593
Loans, net of deferred fees	4,239,492
Non-owner occupied commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of deferred fees	2,398,946
Owner occupied commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of deferred fees	827,092
Multifamily
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of deferred fees	813,225
Non-owner occupied residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of deferred fees	200,229
Commercial, industrial and other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss and fee		431,934
Loans, net of deferred fees	718,189
Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss and fee		335,169
Loans, net of deferred fees	266,883
Equipment finance
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss and fee		111,076
Loans, net of deferred fees	116,690
Residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss and fee		335,191
Loans, net of deferred fees	377,380
Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss and fee		$ 337,977
Loans, net of deferred fees	$ 302,598