Goodwill and Other Intangible Assets (Finite-lived Intangible Assets) (Narrative) (Details) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016 USD ($)	Sep. 30, 2016 USD ($)	Jun. 30, 2016 USD ($)	Mar. 31, 2016 USD ($)	Dec. 31, 2015 USD ($) business	Sep. 30, 2015 USD ($)	Jun. 30, 2015 USD ($)	Mar. 31, 2015 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($) business
Amortized Intangible Assets [Line Items]
Impairment of intangible and other long-lived assets											$ 25,100
Amortization of Intangible Assets
Amortization of intangible assets	$ 7,511	$ 6,620	$ 6,278	$ 6,262	$ 5,120	$ 4,512	$ 4,647	$ 4,738	$ 26,671	$ 19,017	18,187
Estimated amortization of intangible assets, 2017	24,000								24,000
Estimated amortization of intangible assets, 2018	21,000								21,000
Estimated amortization of intangible assets, 2019	20,000								20,000
Estimated amortization of intangible assets, 2020	16,000								16,000
Estimated amortization of intangible assets, 2021	12,000								12,000
Estimated amortization of intangible assets, after 2021	$ 15,000								$ 15,000
Discontinued Operations [Member]
Amortized Intangible Assets [Line Items]
Impairment of intangible and other long-lived assets											7,800
Test Preparation [Member]
Amortized Intangible Assets [Line Items]
Impairment of intangible assets					$ 500						$ 1,800
Number of businesses that recorded impairment of intangible and other long-lived assets | business					1						1
Kaplan International [Member]
Amortized Intangible Assets [Line Items]
Impairment of intangible assets					$ 900						$ 1,100
Number of businesses that recorded impairment of intangible and other long-lived assets | business					1						1
Kaplan International [Member] | Discontinued Operations [Member] | Kaplan China [Member]
Amortized Intangible Assets [Line Items]
Impairment of intangible assets											$ 7,800