Segment Reporting - Financial Information by Reportable Segment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Revenues
Revenues	$ 1,131,686	$ 1,027,653	$ 997,137
Income (loss) from operations
Income (loss) from operations	73,912	109,384	110,532
Amortization of intangible assets	(51,495)	(64,225)	(61,667)
Merger and integration costs	(11,201)	(13,770)	(21,923)
Restructuring costs	(25,472)	(12,382)	0
Segment Reconciling Items
Income (loss) from operations
Amortization of intangible assets	(51,495)	(64,225)	(61,667)
Merger and integration costs	(11,201)	(13,770)	(21,923)
Restructuring costs	(25,472)	(12,382)	0
U.S. Higher Education
Revenues
Revenues	829,270	966,579	963,052
Income (loss) from operations
Income (loss) from operations	104,914	193,393	172,889
Australia / New Zealand
Revenues
Revenues	250,124	23,381	0
Income (loss) from operations
Income (loss) from operations	35,855	(13,275)	0
Education Technology Services
Revenues
Revenues	52,292	37,693	34,085
Income (loss) from operations
Income (loss) from operations	$ 21,311	$ 19,643	$ 21,233