Stock Options and Restricted Shares - Narrative (Details) - USD ($) $ in Thousands		3 Months Ended						9 Months Ended
	Jul. 31, 2015	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2023	Sep. 30, 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense		$ 10,121	$ 9,253	$ 10,199	$ 10,674	$ 10,760	$ 9,448	$ 29,573	$ 30,882
Remaining Share-Based Compensation on Unvested Restricted Stock Awards		$ 72,700						$ 72,700
Weighted Average Remaining Period of Sharebased Compensation Expense								1 year 11 months 4 days
2018 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for issuances (in shares)		928,000						928,000
CapitalMark Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for issuances (in shares)		0						0
Shares acquired in period (in shares)	858,000