Goodwill and Other Intangible Assets (Other Intangible Assets) (Details) 2 (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012 year	Dec. 31, 2011 year
Amortized intangible assets [Abstract]
Useful Life, maximum (in years)	10
Gross Carrying Amount	$ 129,641	$ 146,934
Accumulated Amortization	84,064	92,312
Net Carrying Amount	45,577	54,622
Indefinite Lived Intangible Assets Excluding Goodwill [Line Items]
Indefinite-Lived Intangible Assets, Net	539,728	530,641
Franchise Agreements [Member]
Indefinite Lived Intangible Assets Excluding Goodwill [Line Items]
Indefinite-Lived Intangible Assets, Net	496,321	496,321
Wireless Licenses [Member]
Indefinite Lived Intangible Assets Excluding Goodwill [Line Items]
Indefinite-Lived Intangible Assets, Net	22,150	22,150
Licensure and Accreditation [Member]
Indefinite Lived Intangible Assets Excluding Goodwill [Line Items]
Indefinite-Lived Intangible Assets, Net	7,371	7,862
Other [Member]
Indefinite Lived Intangible Assets Excluding Goodwill [Line Items]
Indefinite-Lived Intangible Assets, Net	13,886	4,308
Non-compete Agreements [Member]
Amortized intangible assets [Abstract]
Useful Life, minimum (in years)	2	2
Useful Life, maximum (in years)	5	5
Gross Carrying Amount	14,008	14,493
Accumulated Amortization	12,546	10,764
Net Carrying Amount	1,462	3,729
Student and Customer Relationships [Member]
Amortized intangible assets [Abstract]
Useful Life, minimum (in years)	2	2
Useful Life, maximum (in years)	10	10
Gross Carrying Amount	73,693	75,734
Accumulated Amortization	40,787	47,888
Net Carrying Amount	32,906	27,846
Databases and Technology [Member]
Amortized intangible assets [Abstract]
Useful Life, minimum (in years)	3	3
Useful Life, maximum (in years)	5	5
Gross Carrying Amount	6,457	10,514
Accumulated Amortization	5,707	8,159
Net Carrying Amount	750	2,355
Trade Names and Trademarks [Member]
Amortized intangible assets [Abstract]
Useful Life, minimum (in years)	2	2
Useful Life, maximum (in years)	10	10
Gross Carrying Amount	26,634	36,222
Accumulated Amortization	18,185	18,936
Net Carrying Amount	8,449	17,286
Other [Member]
Amortized intangible assets [Abstract]
Useful Life, minimum (in years)	1	1
Useful Life, maximum (in years)	25	25
Gross Carrying Amount	8,849	9,971
Accumulated Amortization	6,839	6,565
Net Carrying Amount	$ 2,010	$ 3,406