Business Combinations - Additional Information (Details) student in Thousands, $ in Thousands	Nov. 03, 2020 USD ($)	Dec. 31, 2020 USD ($)	Jul. 29, 2020 industry student	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Business Acquisition [Line Items]
Goodwill		$ 1,318,526		$ 732,075	$ 732,540
Torrens University and Related Assets in Australia and New Zealand (ANZ)
Business Acquisition [Line Items]
Number of students | student			19
Number of industries | industry			5
Purchase price paid in cash at closing	$ 658,400
Value of business acquisition agreement	642,700
Purchase price adjustment	15,700
Net cash increase at closing	11,000
Working capital increase at closing	4,700
Goodwill	$ 546,053
Transaction costs		$ 8,000