Business Segments (Narrative) (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021 segment	Sep. 30, 2020 USD ($)	Sep. 30, 2020 USD ($)
Business Segments [Line Items]
Number of reportable segments | segment	7
Restructuring, Settlement and Impairment Provisions		$ 11,571	$ 42,844
Operating lease cost			9,156
Clyde's Restaurant Group [Member]
Business Segments [Line Items]
Accelerated Depreciation		2,800	5,700
Education [Member] | Operating Segments [Member]
Business Segments [Line Items]
Restructuring, Settlement and Impairment Provisions		11,571	40,354
Operating lease cost			9,156
Other Businesses [Member] | Operating Segments [Member]
Business Segments [Line Items]
Restructuring, Settlement and Impairment Provisions		0	2,490
Operating lease cost			0
Kaplan International [Member] | Reportable Subsegments [Member] | Education [Member] | Operating Segments [Member]
Business Segments [Line Items]
Restructuring, Settlement and Impairment Provisions		959	12,162
Operating lease cost			2,418
Higher Education [Member] | Reportable Subsegments [Member] | Education [Member] | Operating Segments [Member]
Business Segments [Line Items]
Restructuring, Settlement and Impairment Provisions		$ 802	8,006
Operating lease cost			$ 3,442