Revenue Recognition - Narrative (Details) $ in Millions	9 Months Ended
	Sep. 30, 2024 USD ($) term course	Dec. 31, 2023 USD ($)
Graduation Fund [Line Items]
Number of free courses | course	1
Number of successfully completed courses | course	3
Consecutive terms of non attendance in which Graduation Fund credits will be lost | term	1
Contract liabilities, tuition cap	$ 14.7	$ 11.8
Graduation Fund | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-10-01
Graduation Fund [Line Items]
Performance obligation expected timing of satisfaction	12 months
Revenue remaining performance obligation	$ 20.4
Tuition Cap | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-10-01
Graduation Fund [Line Items]
Performance obligation expected timing of satisfaction	12 months
Revenue remaining performance obligation	$ 6.7
Minimum | Graduation Fund | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-10-01
Graduation Fund [Line Items]
Performance obligation expected timing of satisfaction	2 years
Minimum | Australia / New Zealand
Graduation Fund [Line Items]
Deferred contract costs, amortization period	1 year
Maximum | Graduation Fund | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-10-01
Graduation Fund [Line Items]
Performance obligation expected timing of satisfaction	4 years
Maximum | Australia / New Zealand
Graduation Fund [Line Items]
Deferred contract costs, amortization period	2 years