Segment and Geographic Information - Segment Results of Operations (Details) - USD ($) $ in Thousands |
3 Months Ended | 12 Months Ended | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
Dec. 31, 2019 |
Sep. 30, 2019 |
Jun. 30, 2019 |
Mar. 31, 2019 |
Dec. 31, 2018 |
Sep. 30, 2018 |
Jun. 30, 2018 |
Mar. 31, 2018 |
Dec. 31, 2019 |
Dec. 31, 2018 |
Dec. 31, 2017 |
|
| Segment Reporting Information [Line Items] | |||||||||||
| Revenue | $ 163,178 | $ 153,798 | $ 135,461 | $ 122,234 | $ 115,095 | $ 106,963 | $ 97,423 | $ 92,288 | $ 574,671 | $ 411,769 | $ 286,752 |
| Total segment profitability | $ (23,946) | $ 17,655 | $ 11,416 | ||||||||
| Segment profitability margin | (4.20%) | 4.30% | 3.90% | ||||||||
| Graduate Program Segment | |||||||||||
| Segment Reporting Information [Line Items] | |||||||||||
| Revenue | $ 417,206 | $ 348,361 | $ 270,432 | ||||||||
| Total segment profitability | $ 5,770 | $ 16,839 | $ 13,022 | ||||||||
| Segment profitability margin | 1.40% | 4.80% | 4.80% | ||||||||
| Alternative Credential Segment | |||||||||||
| Segment Reporting Information [Line Items] | |||||||||||
| Revenue | $ 157,465 | $ 63,408 | $ 16,320 | ||||||||
| Total segment profitability | $ (29,716) | $ 816 | $ (1,606) | ||||||||
| Segment profitability margin | (18.90%) | 1.30% | (9.80%) | ||||||||