Goodwill and Other Intangible Assets (Other Intangible Assets) (Details 2) - USD ($) $ in Thousands		6 Months Ended	12 Months Ended
		Jun. 30, 2017	Dec. 31, 2016
Amortized Intangible Assets [Line Items]
Gross Carrying Amount		$ 359,290	$ 204,217
Accumulated Amortization		110,953	96,278
Net Carrying Amount		248,337	107,939
Indefinite-Lived Intangible Assets [Line Items]
Indefinite-Lived Intangible Assets, Net		110,060	66,026
Trade Names and Trademarks [Member]
Indefinite-Lived Intangible Assets [Line Items]
Indefinite-Lived Intangible Assets, Net		82,810	65,192
FCC licenses [Member]
Indefinite-Lived Intangible Assets [Line Items]
Indefinite-Lived Intangible Assets, Net		26,600	0
Licensure and Accreditation [Member]
Indefinite-Lived Intangible Assets [Line Items]
Indefinite-Lived Intangible Assets, Net		650	834
Student and Customer Relationships [Member]
Amortized Intangible Assets [Line Items]
Gross Carrying Amount		224,280	129,616
Accumulated Amortization		66,780	55,863
Net Carrying Amount		$ 157,500	$ 73,753
Student and Customer Relationships [Member] | Minimum [Member]
Amortized Intangible Assets [Line Items]
Useful Life	[1]	1 year	2 years
Student and Customer Relationships [Member] | Maximum [Member]
Amortized Intangible Assets [Line Items]
Useful Life	[1]	10 years	10 years
Trade Names and Trademarks [Member]
Amortized Intangible Assets [Line Items]
Gross Carrying Amount		$ 56,995	$ 55,240
Accumulated Amortization		31,920	29,670
Net Carrying Amount		$ 25,075	$ 25,570
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
Network Affiliation Agreements [Member]
Amortized Intangible Assets [Line Items]
Useful Life		15 years
Gross Carrying Amount		$ 42,600	$ 0
Accumulated Amortization		1,302	0
Net Carrying Amount		41,298	0
Databases and Technology [Member]
Amortized Intangible Assets [Line Items]
Gross Carrying Amount		19,505	5,601
Accumulated Amortization		3,321	4,368
Net Carrying Amount		$ 16,184	$ 1,233
Databases and Technology [Member] | Minimum [Member]
Amortized Intangible Assets [Line Items]
Useful Life	[1]	3 years	3 years
Databases and Technology [Member] | Maximum [Member]
Amortized Intangible Assets [Line Items]
Useful Life	[1]	6 years	5 years
Non-compete Agreements [Member]
Amortized Intangible Assets [Line Items]
Gross Carrying Amount		$ 2,180	$ 1,730
Accumulated Amortization		1,480	1,404
Net Carrying Amount		$ 700	$ 326
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		$ 13,730	$ 12,030
Accumulated Amortization		6,150	4,973
Net Carrying Amount		$ 7,580	$ 7,057
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		8 years	8 years

[1] As of December 31, 2016, the student and customer relationships’ minimum useful life was 2 years and the databases and technology’s maximum useful life was 5 years.