Revenue Recognition - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Disaggregation of Revenue [Line Items]
Revenues	$ 290,336	$ 265,302
U.S. Higher Education Segment
Disaggregation of Revenue [Line Items]
Revenues	226,547	255,513
U.S. Higher Education Segment | Tuition, net of discounts, grants and scholarships
Disaggregation of Revenue [Line Items]
Revenues	217,477	245,320
U.S. Higher Education Segment | Other
Disaggregation of Revenue [Line Items]
Revenues	9,070	10,193
Australia/New Zealand Segment
Disaggregation of Revenue [Line Items]
Revenues	51,265	0
Australia/New Zealand Segment | Tuition, net of discounts, grants and scholarships
Disaggregation of Revenue [Line Items]
Revenues	50,222	0
Australia/New Zealand Segment | Other
Disaggregation of Revenue [Line Items]
Revenues	1,043	0
Alternative Learning
Disaggregation of Revenue [Line Items]
Revenues	$ 12,524	$ 9,789