Business, Basis of Financial Statement Presentation and Principles of Consolidation - Additional Information (Details) $ in Thousands			3 Months Ended
	Jun. 05, 2020	Mar. 27, 2020 USD ($)	Mar. 31, 2021 USD ($) Office Loan	Dec. 31, 2020 USD ($)
Business Basis Of Financial Statement Presentation And Principles Of Consolidation [Line Items]
Number of offices | Office			181
Financing receivable, loan amount			$ 679,725	$ 610,134
Small Business Administration (SBA), CARES Act, Paycheck Protection Program [Member]
Business Basis Of Financial Statement Presentation And Principles Of Consolidation [Line Items]
Provision for CARES Act		$ 349,000,000
Financing Receivable, interest rate		1.00%
Financing Receivable, loan term		2 years
Financing receivable, loans outstanding | Loan			7,456
Financing receivable, loan amount			$ 679,700
Financing receivable, deferred fees and costs			$ 22,100
Financing receivable, loans originated | Loan			4,774
Financing receivable, loan amount received			$ 301,500
Financing receivable loan originated deferred fees and cost			$ 16,500
Small Business Administration (SBA), CARES Act, Paycheck Protection Program [Member] | Minimum [Member]
Business Basis Of Financial Statement Presentation And Principles Of Consolidation [Line Items]
Financing Receivable, loan term	5 years
Financing Receivable, processing fee percentage	1.00%
Small Business Administration (SBA), CARES Act, Paycheck Protection Program [Member] | Maximum [Member]
Business Basis Of Financial Statement Presentation And Principles Of Consolidation [Line Items]
Financing receivable, existing loans maturity term	5 years
Financing receivable, guaranteed percentage	100.00%
Financing Receivable, processing fee percentage	5.00%