Other Long-Term Liabilities - Deferred (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020 USD ($) item	Dec. 31, 2019 USD ($)
Other Liabilities, Noncurrent [Line Items]
Asset retirement obligations	$ 7,647	$ 1,961
Deferred payment arrangements value	$ 700	$ 2,200
Deferred payment arrangement number of sellers | item	1
Funds received from investor	$ 2,800
Torrens University and Related Assets in Australia and New Zealand (ANZ)
Other Liabilities, Noncurrent [Line Items]
Asset retirement obligations	$ 5,800