Segment and Geographic Information - Non-cash items (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Non cash items included in segment income (loss) from operations by reportable segment
Depreciation and amortization	$ 103,416	$ 109,154	$ 104,861
Amortization of intangible assets	51,495	64,225	61,667
Stock-based compensation	18,149	14,610	12,160
Segments | U.S. Higher Education
Non cash items included in segment income (loss) from operations by reportable segment
Depreciation and amortization	38,178	41,822	41,962
Stock-based compensation	16,926	14,452	11,445
Segments | Australia / New Zealand
Non cash items included in segment income (loss) from operations by reportable segment
Depreciation and amortization	10,640	1,930	0
Stock-based compensation	1,359	46	0
Segments | Education Technology Services
Non cash items included in segment income (loss) from operations by reportable segment
Depreciation and amortization	1,067	828	831
Stock-based compensation	567	112	348
Segment Reconciling Items
Non cash items included in segment income (loss) from operations by reportable segment
Amortization of intangible assets	51,495	64,225	61,667
Merger and integration costs	0	0	401
Merger and integration costs	0	0	367
Restructuring costs	2,036	349	0
Restructuring costs	$ (703)	$ 0	$ 0