Discontinued Operations and Assets Held for Sale - Loss On Impairment of Assets (Details) $ in Thousands	3 Months Ended		12 Months Ended
	Dec. 31, 2018 USD ($)	Sep. 30, 2018 USD ($)	Dec. 31, 2018 USD ($) institution	Dec. 31, 2017 USD ($) subsidiary	Dec. 31, 2016 USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of discontinued VIE institutions | institution			6
Long-lived assets	$ 1,278,935		$ 1,278,935	$ 1,380,417
Loss on impairment of assets		$ 10,030	13,110	40,597	$ 23,465
Impairments of Goodwill			3,080	0
Discontinued Operations, Held-for-sale or Disposed of by Sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Impairments of long-lived assets			0	$ 33,476	23,465
Central America & U.S. Campuses | Disposal Group, Held-for-sale, Not Discontinued Operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of subsidiaries with impaired long-lived assets (subsidiary) | subsidiary				2
Central America & U.S. Campuses | Tradenames
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Impairment of long-lived assets to be disposed of				$ 17,400
Rest of World
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Long-lived assets				0
Loss on impairment of assets					23,465
Impairments of Goodwill	$ 3,080		$ 3,080	0
Rest of World | GERMANY
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Impairments of Goodwill					4,163
Rest of World | Monash South Africa (MSA)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Impairments of Goodwill					$ 19,302
Rest of World | Tradenames
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Impairment of long-lived assets to be disposed of				$ 16,100