Goodwill and Other Intangible Assets (Other Intangible Assets) (Details 2) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Amortized Intangible Assets [Line Items]
Gross Carrying Amount	$ 204,217	$ 178,747
Accumulated Amortization	96,278	71,556
Net Carrying Amount	107,939	107,191
Indefinite-lived Intangible Assets [Line Items]
Net Carrying Amount	66,026	21,885
Student and Customer Relationships [Member]
Amortized Intangible Assets [Line Items]
Gross Carrying Amount	129,616	108,806
Accumulated Amortization	55,863	40,280
Net Carrying Amount	73,753	68,526
Trade Names and Trademarks [Member]
Amortized Intangible Assets [Line Items]
Gross Carrying Amount	55,240	53,848
Accumulated Amortization	29,670	23,941
Net Carrying Amount	25,570	29,907
Databases and Technology [Member]
Amortized Intangible Assets [Line Items]
Gross Carrying Amount	5,601	4,617
Accumulated Amortization	4,368	4,114
Net Carrying Amount	1,233	503
Non-compete Agreements [Member]
Amortized Intangible Assets [Line Items]
Gross Carrying Amount	1,730	1,381
Accumulated Amortization	1,404	1,012
Net Carrying Amount	326	369
Other [Member]
Amortized Intangible Assets [Line Items]
Gross Carrying Amount	12,030	10,095
Accumulated Amortization	4,973	2,209
Net Carrying Amount	$ 7,057	$ 7,886
Minimum [Member] | Student and Customer Relationships [Member]
Amortized Intangible Assets [Line Items]
Useful Life (in years)	2 years	2 years
Minimum [Member] | Trade Names and Trademarks [Member]
Amortized Intangible Assets [Line Items]
Useful Life (in years)	2 years	2 years
Minimum [Member] | Databases and Technology [Member]
Amortized Intangible Assets [Line Items]
Useful Life (in years)	3 years	3 years
Minimum [Member] | Non-compete Agreements [Member]
Amortized Intangible Assets [Line Items]
Useful Life (in years)	2 years	2 years
Minimum [Member] | Other [Member]
Amortized Intangible Assets [Line Items]
Useful Life (in years)	1 year	1 year
Maximum [Member]
Amortized Intangible Assets [Line Items]
Useful Life (in years)	10 years
Maximum [Member] | Student and Customer Relationships [Member]
Amortized Intangible Assets [Line Items]
Useful Life (in years)	10 years	10 years
Maximum [Member] | Trade Names and Trademarks [Member]
Amortized Intangible Assets [Line Items]
Useful Life (in years)	10 years	10 years
Maximum [Member] | Databases and Technology [Member]
Amortized Intangible Assets [Line Items]
Useful Life (in years)	5 years	5 years
Maximum [Member] | Non-compete Agreements [Member]
Amortized Intangible Assets [Line Items]
Useful Life (in years)	5 years	5 years
Maximum [Member] | Other [Member]
Amortized Intangible Assets [Line Items]
Useful Life (in years)	8 years	8 years
Trade Names and Trademarks [Member]
Indefinite-lived Intangible Assets [Line Items]
Net Carrying Amount	$ 65,192	$ 21,051
Licensure and Accreditation [Member]
Indefinite-lived Intangible Assets [Line Items]
Net Carrying Amount	$ 834	$ 834