Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Disaggregation of Revenue [Line Items]
Revenue	$ 659,436	$ 582,717
Higher Education [Member]
Disaggregation of Revenue [Line Items]
Revenue	99,830	111,111
Professional (U.S.) [Member]
Disaggregation of Revenue [Line Items]
Revenue	33,356	33,199
Test Preparation [Member]
Disaggregation of Revenue [Line Items]
Revenue	59,151	64,568
Kaplan International [Member]
Disaggregation of Revenue [Line Items]
Revenue	183,582	164,562
Kaplan Corporate and Other [Member]
Disaggregation of Revenue [Line Items]
Revenue	285	14
Education Intersegment Eliminations [Member]
Disaggregation of Revenue [Line Items]
Revenue	(705)	(557)
Education [Member]
Disaggregation of Revenue [Line Items]
Revenue	375,499	372,897
Television Broadcasting [Member]
Disaggregation of Revenue [Line Items]
Revenue	108,802	91,496
Manufacturing [Member]
Disaggregation of Revenue [Line Items]
Revenue	117,406	61,898
Healthcare [Member]
Disaggregation of Revenue [Line Items]
Revenue	37,621	36,899
SocialCode [Member]
Disaggregation of Revenue [Line Items]
Revenue	13,299	12,574
Other Businesses [Member]
Disaggregation of Revenue [Line Items]
Revenue	6,833	6,953
Business Intersegment Eliminations [Domain]
Disaggregation of Revenue [Line Items]
Revenue	$ (24)	$ 0