Share-Based Compensation - Schedule of Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total pre-tax share-based compensation expense charged against income	$ 8,985	$ 9,214	$ 8,827
Total recognized tax deficiency related to share-based compensation	(773)	(783)	(217)
Selling, general & administrative expense
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total pre-tax share-based compensation expense charged against income	8,942	9,160	8,767
Costs of services provided
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total pre-tax share-based compensation expense charged against income	43	54	60
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total pre-tax share-based compensation expense charged against income	969	1,253	1,832
Restricted stock, restricted stock units and deferred stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total pre-tax share-based compensation expense charged against income	6,657	6,972	6,367
Performance stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total pre-tax share-based compensation expense charged against income	1,210	819	401
Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total pre-tax share-based compensation expense charged against income	$ 149	$ 170	$ 227