Fair Value Measurements (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Goodwill, Impairment Loss	$ 1,603	$ 0	$ 0	$ 0					$ 1,603	$ 251,401
Impairment of goodwill and other long-lived assets					$ 4,233	$ 248,591	$ 6,876	$ 0	1,603	$ 259,700	$ 17,302
Impairment of intangible and other long-lived assets											25,100
Vocational School Company [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Write-downs of cost method investment	$ (12,000)	$ (15,000)							$ (27,000)
Discontinued Operations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impairment of intangible and other long-lived assets											$ 7,800