Commitments and Contingencies - Standby Letters of Credit, Surety Bonds and Other Commitments (Details) - USD ($) $ in Thousands	1 Months Ended
	Nov. 30, 2016	Mar. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Letters of credit outstanding, amount		$ 156,600	$ 154,400
Surety Bond
Debt Instrument [Line Items]
Guarantee amount, maximum potential amount of payments		11,547	12,162
Cash Collateralized Letter Of Credit - Spain Tax Audits
Debt Instrument [Line Items]
Letters of credit outstanding, amount		35,991	34,746
Non-Collateralized Surety Bond - UAM Brazil | Surety Bond
Debt Instrument [Line Items]
Guarantee amount, maximum potential amount of payments	$ 15,300
Cost of surety bond	$ 1,400
Guarantor obligation, term	P5Y
Kendall College, St. Augustine, Walden University, and NewSchool of Architecture and Design
Debt Instrument [Line Items]
Letters of credit outstanding, amount		$ 105,600	$ 105,600