Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Disaggregation of Revenue [Line Items]
Revenue	$ 674,766	$ 657,225	$ 2,006,879	$ 1,916,029
Kaplan International [Member]
Disaggregation of Revenue [Line Items]
Revenue	167,668	171,259	535,553	507,568
Higher Education [Member]
Disaggregation of Revenue [Line Items]
Revenue	89,269	105,210	275,080	328,161
Test Preparation [Member]
Disaggregation of Revenue [Line Items]
Revenue	67,749	72,680	195,504	212,978
Professional (U.S.) [Member]
Disaggregation of Revenue [Line Items]
Revenue	34,302	28,249	98,715	88,812
Kaplan Corporate and Other [Member]
Disaggregation of Revenue [Line Items]
Revenue	143	49	870	120
Education Intersegment Eliminations [Member]
Disaggregation of Revenue [Line Items]
Revenue	(530)	(642)	(1,617)	(1,438)
Education [Member]
Disaggregation of Revenue [Line Items]
Revenue	358,601	376,805	1,104,105	1,136,201
Television Broadcasting [Member]
Disaggregation of Revenue [Line Items]
Revenue	130,014	101,295	352,902	298,893
Manufacturing [Member]
Disaggregation of Revenue [Line Items]
Revenue	126,028	115,594	369,896	298,164
Healthcare [Member]
Disaggregation of Revenue [Line Items]
Revenue	35,486	40,473	111,315	115,592
SocialCode [Member]
Disaggregation of Revenue [Line Items]
Revenue	13,781	14,497	41,850	41,926
Other Businesses [Member]
Disaggregation of Revenue [Line Items]
Revenue	10,856	8,561	26,856	25,253
Business Intersegment Eliminations [Domain]
Disaggregation of Revenue [Line Items]
Revenue	$ 0	$ 0	$ (45)	$ 0