Goodwill and Other Intangible Assets (Changes in Carrying Amount of Goodwill) (Details 1) $ in Thousands	6 Months Ended
	Jun. 30, 2018 USD ($)
Goodwill [Roll Forward]
Goodwill, beginning balance	$ 1,665,861
Accumulated impairment losses, beginning balance	(366,151)
Goodwill, net, beginning balance	1,299,710
Acquisitions	9,629
Dispositions	(11,191)
Foreign currency exchange rate changes	(17,791)
Goodwill, ending balance	1,626,809
Accumulated impairment losses, ending balance	(346,452)
Goodwill, net, ending balance	1,280,357
Education [Member]
Goodwill [Roll Forward]
Goodwill, beginning balance	1,171,812
Accumulated impairment losses, beginning balance	(350,850)
Goodwill, net, beginning balance	820,962
Acquisitions	9,629
Dispositions	(11,191)
Foreign currency exchange rate changes	(17,791)
Goodwill, ending balance	1,132,760
Accumulated impairment losses, ending balance	(331,151)
Goodwill, net, ending balance	801,609
Education [Member] | Kaplan International [Member]
Goodwill [Roll Forward]
Goodwill, beginning balance	615,861
Accumulated impairment losses, beginning balance	0
Goodwill, net, beginning balance	615,861
Acquisitions	26
Dispositions	0
Foreign currency exchange rate changes	(17,690)
Goodwill, ending balance	598,197
Accumulated impairment losses, ending balance	0
Goodwill, net, ending balance	598,197
Education [Member] | Higher Education [Member]
Goodwill [Roll Forward]
Goodwill, beginning balance	205,494
Accumulated impairment losses, beginning balance	(131,023)
Goodwill, net, beginning balance	74,471
Acquisitions	0
Dispositions	(11,191)
Foreign currency exchange rate changes	(40)
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	166,098
Accumulated impairment losses, beginning balance	(102,259)
Goodwill, net, beginning balance	63,839
Acquisitions	473
Dispositions	0
Foreign currency exchange rate changes	0
Goodwill, ending balance	166,571
Accumulated impairment losses, ending balance	(102,259)
Goodwill, net, ending balance	64,312
Education [Member] | Professional (U.S.) [Member]
Goodwill [Roll Forward]
Goodwill, beginning balance	184,359
Accumulated impairment losses, beginning balance	(117,568)
Goodwill, net, beginning balance	66,791
Acquisitions	9,130
Dispositions	0
Foreign currency exchange rate changes	(61)
Goodwill, ending balance	193,428
Accumulated impairment losses, ending balance	(117,568)
Goodwill, net, ending balance	75,860
Television Broadcasting [Member]
Goodwill [Roll Forward]
Goodwill, beginning balance	190,815
Accumulated impairment losses, beginning balance	0
Goodwill, net, beginning balance	190,815
Acquisitions	0
Dispositions	0
Foreign currency exchange rate changes	0
Goodwill, ending balance	190,815
Accumulated impairment losses, ending balance	0
Goodwill, net, ending balance	190,815
Healthcare [Member]
Goodwill [Roll Forward]
Goodwill, beginning balance	69,409
Accumulated impairment losses, beginning balance	0
Goodwill, net, beginning balance	69,409
Acquisitions	0
Dispositions	0
Foreign currency exchange rate changes	0
Goodwill, ending balance	69,409
Accumulated impairment losses, ending balance	0
Goodwill, net, ending balance	69,409
Other Businesses [Member]
Goodwill [Roll Forward]
Goodwill, beginning balance	233,825
Accumulated impairment losses, beginning balance	(15,301)
Goodwill, net, beginning balance	218,524
Acquisitions	0
Dispositions	0
Foreign currency exchange rate changes	0
Goodwill, ending balance	233,825
Accumulated impairment losses, ending balance	(15,301)
Goodwill, net, ending balance	$ 218,524