Business Combinations - Valuation Methodology (Details) - USD ($) $ in Thousands			12 Months Ended
	Nov. 03, 2020	Aug. 01, 2018	Dec. 31, 2020
Business Acquisition [Line Items]
Weighted average useful life			3 years
Torrens University and Related Assets in Australia and New Zealand (ANZ)
Business Acquisition [Line Items]
Property and equipment, net	$ 41,770
Torrens University and Related Assets in Australia and New Zealand (ANZ) | Relief from royalty approach | Course Content
Business Acquisition [Line Items]
Property and equipment, net	$ 10,000
Torrens University and Related Assets in Australia and New Zealand (ANZ) | Relief from royalty approach | Measurement Input, Long-term Revenue Growth Rate | Course Content | Minimum
Business Acquisition [Line Items]
Property, Plant and Equipment, Measurement Input	5.60%
Torrens University and Related Assets in Australia and New Zealand (ANZ) | Relief from royalty approach | Measurement Input, Long-term Revenue Growth Rate | Course Content | Maximum
Business Acquisition [Line Items]
Property, Plant and Equipment, Measurement Input	6.20%
Torrens University and Related Assets in Australia and New Zealand (ANZ) | Relief from royalty approach | Measurement Input, Long-term Revenue Growth Rate | Trade names | Minimum
Business Acquisition [Line Items]
Indefinite-Lived Intangible Asset, Measurement Input	2.50%
Torrens University and Related Assets in Australia and New Zealand (ANZ) | Relief from royalty approach | Measurement Input, Long-term Revenue Growth Rate | Trade names | Maximum
Business Acquisition [Line Items]
Indefinite-Lived Intangible Asset, Measurement Input	6.30%
Torrens University and Related Assets in Australia and New Zealand (ANZ) | Relief from royalty approach | Measurement Input, Royalty Rate | Course Content
Business Acquisition [Line Items]
Property, Plant and Equipment, Measurement Input	3.00%
Torrens University and Related Assets in Australia and New Zealand (ANZ) | Relief from royalty approach | Measurement Input, Royalty Rate | Trade names
Business Acquisition [Line Items]
Indefinite-Lived Intangible Asset, Measurement Input	2.50%
Torrens University and Related Assets in Australia and New Zealand (ANZ) | Relief from royalty approach | Measurement Input, Discount Rate | Course Content
Business Acquisition [Line Items]
Property, Plant and Equipment, Measurement Input	11.00%
Torrens University and Related Assets in Australia and New Zealand (ANZ) | Relief from royalty approach | Measurement Input, Discount Rate | Trade names
Business Acquisition [Line Items]
Indefinite-Lived Intangible Asset, Measurement Input	11.00%
Torrens University and Related Assets in Australia and New Zealand (ANZ) | Cost approach
Business Acquisition [Line Items]
Contract Liabilities Fair Value, Percentage of Carrying Value	70.00%
Capella Merger
Business Acquisition [Line Items]
Property and equipment, net		$ 53,182
Capella Merger | Relief from royalty approach | Course Content
Business Acquisition [Line Items]
Property and equipment, net		$ 14,000
Capella Merger | Relief from royalty approach | Measurement Input, Long-term Revenue Growth Rate | Course Content
Business Acquisition [Line Items]
Property, Plant and Equipment, Measurement Input		2.50%
Capella Merger | Relief from royalty approach | Measurement Input, Long-term Revenue Growth Rate | Trade names
Business Acquisition [Line Items]
Indefinite-Lived Intangible Asset, Measurement Input		2.50%
Capella Merger | Relief from royalty approach | Measurement Input, Royalty Rate | Course Content
Business Acquisition [Line Items]
Property, Plant and Equipment, Measurement Input		3.00%
Capella Merger | Relief from royalty approach | Measurement Input, Royalty Rate | Trade names
Business Acquisition [Line Items]
Indefinite-Lived Intangible Asset, Measurement Input		5.00%
Capella Merger | Relief from royalty approach | Measurement Input, Discount Rate | Course Content
Business Acquisition [Line Items]
Property, Plant and Equipment, Measurement Input		10.00%
Capella Merger | Relief from royalty approach | Measurement Input, Discount Rate | Trade names
Business Acquisition [Line Items]
Indefinite-Lived Intangible Asset, Measurement Input		13.00%
Capella Merger | Cost approach
Business Acquisition [Line Items]
Contract Liabilities Fair Value, Percentage of Carrying Value		58.00%
Capella Merger | Cost approach | Course Content
Business Acquisition [Line Items]
Property and equipment, net		$ 5,000
Student relationships | Torrens University and Related Assets in Australia and New Zealand (ANZ)
Business Acquisition [Line Items]
Weighted average useful life	3 years
Student relationships | Torrens University and Related Assets in Australia and New Zealand (ANZ) | Relief from royalty approach | Course Content
Business Acquisition [Line Items]
Weighted average useful life	3 years
Student relationships | Torrens University and Related Assets in Australia and New Zealand (ANZ) | Valuation Technique, Excess Earnings Method | Measurement Input, Discount Rate
Business Acquisition [Line Items]
Finite-Lived Intangible Asset, Measurement Input	11.00%
Student relationships | Torrens University and Related Assets in Australia and New Zealand (ANZ) | Valuation Technique, Excess Earnings Method | Measurement Input, Annual Attrition Rate
Business Acquisition [Line Items]
Finite-Lived Intangible Asset, Measurement Input	60.00%
Student relationships | Capella Merger
Business Acquisition [Line Items]
Weighted average useful life		3 years
Student relationships | Capella Merger | Course Content
Business Acquisition [Line Items]
Weighted average useful life		3 years
Student relationships | Capella Merger | Valuation Technique, Excess Earnings Method | Measurement Input, Discount Rate
Business Acquisition [Line Items]
Finite-Lived Intangible Asset, Measurement Input		10.00%
Student relationships | Capella Merger | Valuation Technique, Excess Earnings Method | Measurement Input, Annual Attrition Rate
Business Acquisition [Line Items]
Finite-Lived Intangible Asset, Measurement Input		45.00%