Goodwill and Other Intangible Assets (Narrative) (Details) (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Amortized Intangible Assets [Line Items]
Impairment of intangible and other long-lived assets	$ 17,302,000	$ 0	$ 0	$ 0	$ 3,250,000	$ 0	$ 0	$ 0	$ 25,100,000	$ 3,300,000
Goodwill and other long-lived asset impairment charges									17,302,000	3,250,000	111,593,000
Indefinite-lived Intangible Assets [Line Items]
Gain on sale of intangible asset									75,249,000	0	0
Amortization of Intangible Assets
Amortization of intangible assets	5,251,000	7,405,000	2,995,000	2,717,000	3,359,000	2,468,000	2,950,000	3,362,000	18,368,000	12,139,000	19,510,000
Estimated amortization of intangible assets, 2015	19,000,000								19,000,000
Estimated amortization of intangible assets, 2016	18,000,000								18,000,000
Estimated amortization of intangible assets, 2017	14,000,000								14,000,000
Estimated amortization of intangible assets, 2018	13,000,000								13,000,000
Estimated amortization of intangible assets, 2019	12,000,000								12,000,000
Estimated amortization of intangible assets, after 2019	21,000,000								21,000,000
Discontinued Operations [Member]
Amortized Intangible Assets [Line Items]
Impairment of intangible and other long-lived assets									7,800,000
Cable [Member] | Wireless Licenses [Member]
Indefinite-lived Intangible Assets [Line Items]
Gain on sale of intangible asset		75,200,000
Kaplan International [Member]
Amortized Intangible Assets [Line Items]
Impairment of intangible assets									1,100,000
Number of businesses that recorded impairment of intangible and other long-lived assets									1	1
Impairment of intangible and other long-lived assets										3,300,000
Kaplan International [Member] | Discontinued Operations [Member] | Kaplan China [Member]
Amortized Intangible Assets [Line Items]
Impairment of intangible assets									7,800,000
Test Preparation [Member]
Amortized Intangible Assets [Line Items]
Impairment of intangible assets									1,800,000
Goodwill and other long-lived asset impairment charges											111,600,000
Higher Education [Member]
Indefinite-lived Intangible Assets [Line Items]
Impairment of intangible assets									700,000
Other Businesses [Member]
Amortized Intangible Assets [Line Items]
Number of businesses that recorded impairment of intangible and other long-lived assets									1
Indefinite-lived Intangible Assets [Line Items]
Impairment of intangible assets									$ 100,000