Share-Based Compensation - Schedule of Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total pre-tax stock-based compensation expense charged against income	$ 6,793	$ 7,156
Selling, general & administrative expense
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total pre-tax stock-based compensation expense charged against income	6,723	7,063
Costs of services provided
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total pre-tax stock-based compensation expense charged against income	70	93
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total pre-tax stock-based compensation expense charged against income	716	939
Restricted stock, restricted stock units and deferred stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total pre-tax stock-based compensation expense charged against income	4,946	5,310
Performance stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total pre-tax stock-based compensation expense charged against income	888	612
Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total pre-tax stock-based compensation expense charged against income	$ 243	$ 295