Revenue - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Disaggregation of Revenue [Line Items]
Accounts and notes receivable	$ 117,987	$ 138,738
Deferred revenue and student deposits, current	43,959	47,180
Capitalized contract cost	5,800	4,000
Capitalized contract cost, accumulated amortization	3,100	1,900
Amortization of capitalized costs	$ 1,400	$ 1,100
Minimum
Disaggregation of Revenue [Line Items]
Contract cost, amortization period	2 years
Maximum
Disaggregation of Revenue [Line Items]
Contract cost, amortization period	4 years
Commission and Bonuses
Disaggregation of Revenue [Line Items]
Remaining performance obligations recognition period	one year or less
Incremental Cost of Obtaining a Contract With Students
Disaggregation of Revenue [Line Items]
Remaining performance obligations recognition period	one year or less