Revenue from Contracts with Customers (Disaggregation of Revenue) (Details 1) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Disaggregation of Revenue [Line Items]
Revenue	$ 692,199	$ 659,436
Intersegment Eliminations [Member]
Disaggregation of Revenue [Line Items]
Revenue	(40)	(24)
Kaplan International [Member]
Disaggregation of Revenue [Line Items]
Revenue	185,756	183,582
Higher Education [Member]
Disaggregation of Revenue [Line Items]
Revenue	82,780	99,830
Test Preparation [Member]
Disaggregation of Revenue [Line Items]
Revenue	61,150	59,151
Professional (U.S.) [Member]
Disaggregation of Revenue [Line Items]
Revenue	41,214	33,356
Kaplan Corporate and Other [Member]
Disaggregation of Revenue [Line Items]
Revenue	2,302	285
Education Intersegment Eliminations [Member]
Disaggregation of Revenue [Line Items]
Revenue	(748)	(705)
Education [Member]
Disaggregation of Revenue [Line Items]
Revenue	372,454	375,499
Television Broadcasting [Member]
Disaggregation of Revenue [Line Items]
Revenue	108,223	108,802
Manufacturing [Member]
Disaggregation of Revenue [Line Items]
Revenue	115,157	117,406
Healthcare [Member]
Disaggregation of Revenue [Line Items]
Revenue	37,728	37,621
SocialCode [Member]
Disaggregation of Revenue [Line Items]
Revenue	13,447	13,299
Other Businesses [Member]
Disaggregation of Revenue [Line Items]
Revenue	$ 45,230	$ 6,833