Goodwill and Other Intangible Assets (Other Intangible Assets) (Details) 2 (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
	Mar. 31, 2014	Dec. 31, 2013
Amortized Intangible Assets [Line Items]
Gross Carrying Amount	$ 122,735	$ 128,543
Accumulated Amortization	86,241	88,955
Net Carrying Amount	36,494	39,588
Indefinite-Lived Intangible Assets [Line Items]
Indefinite-Lived Intangible Assets, Net	519,128	541,278
Franchise Agreements [Member]
Indefinite-Lived Intangible Assets [Line Items]
Indefinite-Lived Intangible Assets, Net	496,321	496,321
Wireless Licenses [Member]
Indefinite-Lived Intangible Assets [Line Items]
Indefinite-Lived Intangible Assets, Net	0	22,150
Licensure and Accreditation [Member]
Indefinite-Lived Intangible Assets [Line Items]
Indefinite-Lived Intangible Assets, Net	7,171	7,171
Other [Member]
Indefinite-Lived Intangible Assets [Line Items]
Indefinite-Lived Intangible Assets, Net	15,636	15,636
Non-compete Agreements [Member]
Amortized Intangible Assets [Line Items]
Gross Carrying Amount	13,565	13,540
Accumulated Amortization	12,737	12,622
Net Carrying Amount	828	918
Non-compete Agreements [Member] | Minimum [Member]
Amortized Intangible Assets [Line Items]
Useful Life	2 years	2 years
Non-compete Agreements [Member] | Maximum [Member]
Amortized Intangible Assets [Line Items]
Useful Life	5 years	5 years
Student and Customer Relationships [Member]
Amortized Intangible Assets [Line Items]
Gross Carrying Amount	66,163	72,050
Accumulated Amortization	41,725	45,718
Net Carrying Amount	24,438	26,332
Student and Customer Relationships [Member] | Minimum [Member]
Amortized Intangible Assets [Line Items]
Useful Life	2 years	2 years
Student and Customer Relationships [Member] | Maximum [Member]
Amortized Intangible Assets [Line Items]
Useful Life	10 years	10 years
Databases and Technology [Member]
Amortized Intangible Assets [Line Items]
Gross Carrying Amount	10,790	10,790
Accumulated Amortization	7,331	6,991
Net Carrying Amount	3,459	3,799
Databases and Technology [Member] | Minimum [Member]
Amortized Intangible Assets [Line Items]
Useful Life	3 years	3 years
Databases and Technology [Member] | Maximum [Member]
Amortized Intangible Assets [Line Items]
Useful Life	5 years	5 years
Trade Names and Trademarks [Member]
Amortized Intangible Assets [Line Items]
Gross Carrying Amount	22,359	22,327
Accumulated Amortization	16,660	16,052
Net Carrying Amount	5,699	6,275
Trade Names and Trademarks [Member] | Minimum [Member]
Amortized Intangible Assets [Line Items]
Useful Life	2 years	2 years
Trade Names and Trademarks [Member] | Maximum [Member]
Amortized Intangible Assets [Line Items]
Useful Life	10 years	10 years
Other [Member]
Amortized Intangible Assets [Line Items]
Gross Carrying Amount	9,858	9,836
Accumulated Amortization	7,788	7,572
Net Carrying Amount	$ 2,070	$ 2,264
Other [Member] | Minimum [Member]
Amortized Intangible Assets [Line Items]
Useful Life	1 year	1 year
Other [Member] | Maximum [Member]
Amortized Intangible Assets [Line Items]
Useful Life	25 years	25 years