Assets Held for Sale - Summary of Major Classes of Assets and Liabilities Reclassified to Held for Sale (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Long-term assets held for sale	$ 311,231	$ 392,391
Disposal Group, Held-for-sale, Not Discontinued Operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Property and equipment, net	195,770
Goodwill	68,459
Tradenames	32,312
Other long-term assets	14,690
Long-term assets held for sale	311,231
Deferred revenue and student deposits	46,335	$ 94,951
Long-term debt, including current portion	78,289
Other liabilities	65,569
Total liabilities held for sale	$ 190,193