Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Disaggregation of Revenue [Line Items]
Revenue	$ 672,677	$ 676,087	$ 1,332,113	$ 1,258,804
Kaplan International [Member]
Disaggregation of Revenue [Line Items]
Revenue	184,303	171,747	367,885	336,309
Higher Education [Member]
Disaggregation of Revenue [Line Items]
Revenue	85,981	111,840	185,811	222,951
Test Preparation [Member]
Disaggregation of Revenue [Line Items]
Revenue	68,604	75,730	127,755	140,298
Professional (U.S.) [Member]
Disaggregation of Revenue [Line Items]
Revenue	31,057	27,364	64,413	60,563
Kaplan Corporate and Other [Member]
Disaggregation of Revenue [Line Items]
Revenue	442	57	727	71
Education Intersegment Eliminations [Member]
Disaggregation of Revenue [Line Items]
Revenue	(382)	(239)	(1,087)	(796)
Education [Member]
Disaggregation of Revenue [Line Items]
Revenue	370,005	386,499	745,504	759,396
Television Broadcasting [Member]
Disaggregation of Revenue [Line Items]
Revenue	114,086	106,102	222,888	197,598
Manufacturing [Member]
Disaggregation of Revenue [Line Items]
Revenue	126,462	120,672	243,868	182,570
Healthcare [Member]
Disaggregation of Revenue [Line Items]
Revenue	38,208	38,220	75,829	75,119
SocialCode [Member]
Disaggregation of Revenue [Line Items]
Revenue	14,770	14,855	28,069	27,429
Other Businesses [Member]
Disaggregation of Revenue [Line Items]
Revenue	9,167	9,739	16,000	16,692
Business Intersegment Eliminations [Domain]
Disaggregation of Revenue [Line Items]
Revenue	$ (21)	$ 0	$ (45)	$ 0