Goodwill and Other Intangible Assets (Changes in Carrying Amount of Goodwill) (Details 1) $ in Thousands	9 Months Ended
	Sep. 30, 2020 USD ($)
Goodwill [Roll Forward]
Goodwill, beginning balance	$ 1,734,731
Accumulated impairment losses, beginning balance	(346,452)
Goodwill, net, beginning balance	1,388,279
Measurement period adjustments	154
Acquisitions	76,609
Impairment	(6,878)
Foreign currency exchange rate changes	30
Goodwill, ending balance	1,811,524
Accumulated impairment losses, ending balance	(353,330)
Goodwill, net, ending balance	1,458,194
Education [Member]
Goodwill [Roll Forward]
Goodwill, beginning balance	1,140,958
Accumulated impairment losses, beginning balance	(331,151)
Goodwill, net, beginning balance	809,807
Measurement period adjustments	154
Acquisitions	13,022
Impairment	0
Foreign currency exchange rate changes	30
Goodwill, ending balance	1,154,164
Accumulated impairment losses, ending balance	(331,151)
Goodwill, net, ending balance	823,013
Education [Member] | Kaplan International [Member]
Goodwill [Roll Forward]
Goodwill, beginning balance	595,604
Accumulated impairment losses, beginning balance	0
Goodwill, net, beginning balance	595,604
Measurement period adjustments	154
Acquisitions	9,788
Foreign currency exchange rate changes	74
Goodwill, ending balance	605,620
Accumulated impairment losses, ending balance	0
Goodwill, net, ending balance	605,620
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
Measurement period adjustments	0
Acquisitions	0
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] | Test Preparation [Member]
Goodwill [Roll Forward]
Goodwill, beginning balance	166,920
Accumulated impairment losses, beginning balance	(102,259)
Goodwill, net, beginning balance	64,661
Measurement period adjustments	0
Acquisitions	0
Foreign currency exchange rate changes	0
Goodwill, ending balance	166,920
Accumulated impairment losses, ending balance	(102,259)
Goodwill, net, ending balance	64,661
Education [Member] | Professional (U.S.) [Member]
Goodwill [Roll Forward]
Goodwill, beginning balance	203,870
Accumulated impairment losses, beginning balance	(117,568)
Goodwill, net, beginning balance	86,302
Measurement period adjustments	0
Acquisitions	3,234
Foreign currency exchange rate changes	(44)
Goodwill, ending balance	207,060
Accumulated impairment losses, ending balance	(117,568)
Goodwill, net, ending balance	89,492
Television Broadcasting [Member]
Goodwill [Roll Forward]
Goodwill, beginning balance	190,815
Accumulated impairment losses, beginning balance	0
Goodwill, net, beginning balance	190,815
Measurement period adjustments	0
Acquisitions	0
Impairment	0
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
Measurement period adjustments	0
Acquisitions	0
Impairment	0
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
Measurement period adjustments	0
Acquisitions	0
Impairment	0
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	69,544
Accumulated impairment losses, beginning balance	(7,685)
Goodwill, net, beginning balance	61,859
Measurement period adjustments	0
Acquisitions	63,587
Impairment	(6,878)
Foreign currency exchange rate changes	0
Goodwill, ending balance	133,131
Accumulated impairment losses, ending balance	(14,563)
Goodwill, net, ending balance	$ 118,568