Goodwill and Intangible Assets - Changes in Carrying Amount of Goodwill (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
Goodwill [Line Items]
Goodwill		$ 1,080,858
Accumulated impairment losses		(455,892)
Goodwill	$ 625,711	624,966
Goodwill recorded in connection with a business acquisition	745
Healthcare
Goodwill [Line Items]
Goodwill		644,238
Accumulated impairment losses		(190,024)
Goodwill	454,959	454,214
Goodwill recorded in connection with a business acquisition	745
Education
Goodwill [Line Items]
Goodwill		123,652
Accumulated impairment losses		(1,417)
Goodwill	122,235	122,235
Goodwill recorded in connection with a business acquisition	0
Commercial:
Goodwill [Line Items]
Goodwill		312,968
Accumulated impairment losses		(264,451)
Goodwill	48,517	$ 48,517
Goodwill recorded in connection with a business acquisition	$ 0