Goodwill and Other Intangible Assets (Narrative) (Details) (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Goodwill [Line Items]
Goodwill and other long-lived asset impairment charges	$ 3,250,000	$ 0	$ 0	$ 0	$ 111,593,000	$ 0	$ 0	$ 0	$ 3,250,000	$ 111,593,000	$ 0
Amortization of Intangible Assets
Amortization of intangible assets	3,731,000	2,837,000	3,313,000	3,717,000	7,610,000	5,090,000	4,407,000	3,839,000	13,598,000	20,946,000	22,201,000
Estimated amortization of intangible assets, 2014	11,000,000								11,000,000
Estimated amortization of intangible assets, 2015	9,000,000								9,000,000
Estimated amortization of intangible assets, 2016	8,000,000								8,000,000
Estimated amortization of intangible assets, 2017	5,000,000								5,000,000
Estimated amortization of intangible assets, 2018	4,000,000								4,000,000
Estimated amortization of intangible assets, after 2018	3,000,000								3,000,000
Kaplan International [Member]
Goodwill [Line Items]
Number of businesses that recorded impairment of intangible and other long-lived assets									1
Goodwill and other long-lived asset impairment charges									$ 3,300,000