Goodwill and Other Intangible Assets (Other Intangible Assets) (Details 2) - USD ($) $ in Thousands		9 Months Ended	12 Months Ended
		Sep. 30, 2016	Dec. 31, 2015
Amortized Intangible Assets [Line Items]
Gross Carrying Amount		$ 204,348	$ 178,747
Accumulated Amortization		89,712	71,556
Net Carrying Amount		114,636	107,191
Indefinite-Lived Intangible Assets [Line Items]
Indefinite-Lived Intangible Assets, Net		68,780	21,885
Trade Names and Trademarks [Member]
Indefinite-Lived Intangible Assets [Line Items]
Indefinite-Lived Intangible Assets, Net		67,946	21,051
Licensure and Accreditation [Member]
Indefinite-Lived Intangible Assets [Line Items]
Indefinite-Lived Intangible Assets, Net		834	834
Student and Customer Relationships [Member]
Amortized Intangible Assets [Line Items]
Gross Carrying Amount		130,264	108,806
Accumulated Amortization		51,902	40,280
Net Carrying Amount		$ 78,362	$ 68,526
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
Trade Names and Trademarks [Member]
Amortized Intangible Assets [Line Items]
Gross Carrying Amount		$ 55,705	$ 53,848
Accumulated Amortization		27,929	23,941
Net Carrying Amount		$ 27,776	$ 29,907
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
Databases and Technology [Member]
Amortized Intangible Assets [Line Items]
Gross Carrying Amount		$ 4,617	$ 4,617
Accumulated Amortization		4,304	4,114
Net Carrying Amount		$ 313	$ 503
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
Non-compete Agreements [Member]
Amortized Intangible Assets [Line Items]
Gross Carrying Amount		$ 1,731	$ 1,381
Accumulated Amortization		1,273	1,012
Net Carrying Amount		$ 458	$ 369
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
Other [Member]
Amortized Intangible Assets [Line Items]
Gross Carrying Amount		$ 12,031	$ 10,095
Accumulated Amortization		4,304	2,209
Net Carrying Amount		$ 7,727	$ 7,886
Other [Member] | Minimum [Member]
Amortized Intangible Assets [Line Items]
Useful Life	[1]	1 year	1 year
Other [Member] | Maximum [Member]
Amortized Intangible Assets [Line Items]
Useful Life	[1]	8 years	7 years

[1] The Company's other amortized intangible assets’ maximum useful life was 7 years as of December 31, 2015.