Acquisitions and Dispositions of Businesses (Significant Component) (Details 3) - Kaplan University Transaction [Member] - Education [Member] - Higher Education [Member] - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Not Discontinued Operation, Revenue	$ 0	$ 105,036	$ 91,526	$ 327,529
Disposal Group, Not Discontinued Operation, Operating Income	$ 0	$ 1,785	$ 213	$ 18,582

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

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