Business Combinations - Revenue and Net Loss (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Business Acquisition [Line Items]
Revenues	$ 1,131,686	$ 1,027,653	$ 997,137
Net income	$ 55,087	86,268	$ 81,138
Torrens University and Related Assets in Australia and New Zealand (ANZ)
Business Acquisition [Line Items]
Revenues		23,400
Net income		$ (10,500)