Goodwill and Other Intangible Assets (Changes in Carrying Amount of Goodwill) (Details 1) $ in Thousands	3 Months Ended
	Mar. 31, 2021 USD ($)
Goodwill [Roll Forward]
Goodwill, beginning balance	$ 1,838,080
Accumulated impairment losses, beginning balance	(353,330)
Goodwill, net, beginning balance	1,484,750
Foreign currency exchange rate changes	387
Goodwill, ending balance	1,838,467
Accumulated impairment losses, ending balance	(353,330)
Goodwill, net, ending balance	1,485,137
Education [Member]
Goodwill [Roll Forward]
Goodwill, beginning balance	1,183,379
Accumulated impairment losses, beginning balance	(331,151)
Goodwill, net, beginning balance	852,228
Foreign currency exchange rate changes	387
Goodwill, ending balance	1,183,766
Accumulated impairment losses, ending balance	(331,151)
Goodwill, net, ending balance	852,615
Education [Member] | Kaplan International [Member]
Goodwill [Roll Forward]
Goodwill, beginning balance	634,749
Accumulated impairment losses, beginning balance	0
Goodwill, net, beginning balance	634,749
Foreign currency exchange rate changes	361
Goodwill, ending balance	635,110
Accumulated impairment losses, ending balance	0
Goodwill, net, ending balance	635,110
Education [Member] | Higher Education [Member]
Goodwill [Roll Forward]
Goodwill, beginning balance	174,564
Accumulated impairment losses, beginning balance	(111,324)
Goodwill, net, beginning balance	63,240
Foreign currency exchange rate changes	0
Goodwill, ending balance	174,564
Accumulated impairment losses, ending balance	(111,324)
Goodwill, net, ending balance	63,240
Education [Member] | Supplemental Education [Member]
Goodwill [Roll Forward]
Goodwill, beginning balance	374,066
Accumulated impairment losses, beginning balance	(219,827)
Goodwill, net, beginning balance	154,239
Foreign currency exchange rate changes	26
Goodwill, ending balance	374,092
Accumulated impairment losses, ending balance	(219,827)
Goodwill, net, ending balance	154,265
Television Broadcasting [Member]
Goodwill [Roll Forward]
Goodwill, beginning balance	190,815
Accumulated impairment losses, beginning balance	0
Goodwill, net, beginning balance	190,815
Foreign currency exchange rate changes	0
Goodwill, ending balance	190,815
Accumulated impairment losses, ending balance	0
Goodwill, net, ending balance	190,815
Manufacturing [Member]
Goodwill [Roll Forward]
Goodwill, beginning balance	234,993
Accumulated impairment losses, beginning balance	(7,616)
Goodwill, net, beginning balance	227,377
Foreign currency exchange rate changes	0
Goodwill, ending balance	234,993
Accumulated impairment losses, ending balance	(7,616)
Goodwill, net, ending balance	227,377
Healthcare [Member]
Goodwill [Roll Forward]
Goodwill, beginning balance	98,421
Accumulated impairment losses, beginning balance	0
Goodwill, net, beginning balance	98,421
Foreign currency exchange rate changes	0
Goodwill, ending balance	98,421
Accumulated impairment losses, ending balance	0
Goodwill, net, ending balance	98,421
Other Businesses [Member]
Goodwill [Roll Forward]
Goodwill, beginning balance	130,472
Accumulated impairment losses, beginning balance	(14,563)
Goodwill, net, beginning balance	115,909
Foreign currency exchange rate changes	0
Goodwill, ending balance	130,472
Accumulated impairment losses, ending balance	(14,563)
Goodwill, net, ending balance	$ 115,909