Goodwill and Intangible Assets - Schedule of Goodwill (Details) - USD ($)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Changes in carrying amount
Balance, beginning of period	$ 1,285,864,000	$ 1,318,526,000
Reporting unit reallocation		0
Additions	947,000	0
Impairments	0	0	$ 0
Currency translation adjustments	(35,621,000)	(32,924,000)
Adjustments to prior acquisitions	87,000	262,000
Balance, end of period	1,251,277,000	1,285,864,000	1,318,526,000
U.S. Higher Education
Changes in carrying amount
Balance, beginning of period	632,075,000	732,075,000
Reporting unit reallocation		(100,000,000)
Additions	0	0
Impairments	0	0
Currency translation adjustments	0	0
Adjustments to prior acquisitions	0	0
Balance, end of period	632,075,000	632,075,000	732,075,000
Australia / New Zealand
Changes in carrying amount
Balance, beginning of period	553,789,000	586,451,000
Reporting unit reallocation		0
Additions	947,000	0
Impairments	0	0
Currency translation adjustments	(35,621,000)	(32,924,000)
Adjustments to prior acquisitions	87,000	262,000
Balance, end of period	519,202,000	553,789,000	586,451,000
Education Technology Services
Changes in carrying amount
Balance, beginning of period	100,000,000	0
Reporting unit reallocation		100,000,000
Additions	0	0
Impairments	0	0
Currency translation adjustments	0	0
Adjustments to prior acquisitions	0	0
Balance, end of period	$ 100,000,000	$ 100,000,000	$ 0