Goodwill and Other Intangible Assets (Changes in Carrying Amount of Goodwill) (Details 1) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2017
Goodwill [Roll Forward]
Goodwill, beginning balance		$ 1,481,489
Accumulated impairment losses, beginning balance		(358,535)
Goodwill, net, beginning balance		1,122,954
Acquisitions		143,433
Impairment		(7,616)
Dispositions		(412)
Foreign currency exchange rate changes		40,867
Goodwill, ending balance		1,665,377
Accumulated impairment losses, ending balance		(366,151)
Goodwill, net, ending balance		1,299,226
Education [Member]
Goodwill [Roll Forward]
Goodwill, beginning balance		1,111,003
Accumulated impairment losses, beginning balance		(350,850)
Goodwill, net, beginning balance		760,153
Acquisitions		18,986
Impairment		0
Dispositions		0
Foreign currency exchange rate changes		40,867
Goodwill, ending balance		1,170,856
Accumulated impairment losses, ending balance		(350,850)
Goodwill, net, ending balance		820,006
Education [Member] | Higher Education [Member]
Goodwill [Roll Forward]
Goodwill, beginning balance		389,720
Accumulated impairment losses, beginning balance		(248,591)
Goodwill, net, beginning balance		141,129
Acquisitions		0
Impairment	$ (248,600)
Foreign currency exchange rate changes		154
Goodwill, ending balance		389,874
Accumulated impairment losses, ending balance		(248,591)
Goodwill, net, ending balance		141,283
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		0
Foreign currency exchange rate changes		0
Goodwill, ending balance		166,098
Accumulated impairment losses, ending balance		(102,259)
Goodwill, net, ending balance		63,839
Education [Member] | Kaplan International [Member]
Goodwill [Roll Forward]
Goodwill, beginning balance		555,185
Accumulated impairment losses, beginning balance		0
Goodwill, net, beginning balance		555,185
Acquisitions		18,986
Foreign currency exchange rate changes		40,713
Goodwill, ending balance		614,884
Accumulated impairment losses, ending balance		0
Goodwill, net, ending balance		614,884
Television Broadcasting [Member]
Goodwill [Roll Forward]
Goodwill, beginning balance		168,345
Accumulated impairment losses, beginning balance		0
Goodwill, net, beginning balance		168,345
Acquisitions		24,256
Impairment		0
Dispositions		0
Foreign currency exchange rate changes		0
Goodwill, ending balance		192,601
Accumulated impairment losses, ending balance		0
Goodwill, net, ending balance		192,601
Other Businesses [Member]
Goodwill [Roll Forward]
Goodwill, beginning balance		202,141
Accumulated impairment losses, beginning balance		(7,685)
Goodwill, net, beginning balance		194,456
Acquisitions		100,191
Impairment		(7,616)
Dispositions		(412)
Foreign currency exchange rate changes		0
Goodwill, ending balance		301,920
Accumulated impairment losses, ending balance		(15,301)
Goodwill, net, ending balance		$ 286,619