Revenue from Contracts with Customers (Disaggregation of Revenue) (Details 1) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Disaggregation of Revenue [Line Items]
Revenue	$ 737,602	$ 672,677	$ 1,429,801	$ 1,332,113
Intersegment Eliminations [Member]
Disaggregation of Revenue [Line Items]
Revenue	(44)	(21)	(84)	(45)
Kaplan International [Member]
Disaggregation of Revenue [Line Items]
Revenue	188,580	184,303	374,336	367,885
Higher Education [Member]
Disaggregation of Revenue [Line Items]
Revenue	76,288	85,981	159,068	185,811
Test Preparation [Member]
Disaggregation of Revenue [Line Items]
Revenue	65,673	68,604	126,823	127,755
Professional (U.S.) [Member]
Disaggregation of Revenue [Line Items]
Revenue	35,147	31,057	76,361	64,413
Kaplan Corporate and Other [Member]
Disaggregation of Revenue [Line Items]
Revenue	2,369	442	4,671	727
Education Intersegment Eliminations [Member]
Disaggregation of Revenue [Line Items]
Revenue	(294)	(382)	(1,042)	(1,087)
Education [Member]
Disaggregation of Revenue [Line Items]
Revenue	367,763	370,005	740,217	745,504
Television Broadcasting [Member]
Disaggregation of Revenue [Line Items]
Revenue	116,628	114,086	224,851	222,888
Manufacturing [Member]
Disaggregation of Revenue [Line Items]
Revenue	114,873	126,462	230,030	243,868
Healthcare [Member]
Disaggregation of Revenue [Line Items]
Revenue	40,641	38,208	78,369	75,829
SocialCode [Member]
Disaggregation of Revenue [Line Items]
Revenue	16,382	14,770	29,829	28,069
Other Businesses [Member]
Disaggregation of Revenue [Line Items]
Revenue	$ 81,359	$ 9,167	$ 126,589	$ 16,000