Goodwill and Other Intangible Assets (Other Intangible Assets) (Details 2) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Amortized Intangible Assets [Line Items]
Gross Carrying Amount	$ 452,952	$ 440,105
Accumulated Amortization	219,471	176,844
Net Carrying Amount	233,481	263,261
Indefinite-lived Intangible Assets [Line Items]
Net Carrying Amount	140,197	99,052
Student and Customer Relationships [Member]
Amortized Intangible Assets [Line Items]
Gross Carrying Amount	291,626	282,761
Accumulated Amortization	144,625	114,429
Net Carrying Amount	147,001	168,332
Trade Names and Trademarks [Member]
Amortized Intangible Assets [Line Items]
Gross Carrying Amount	87,190	87,285
Accumulated Amortization	42,770	39,825
Net Carrying Amount	$ 44,420	$ 47,460
Network affiliation agreements [Member]
Amortized Intangible Assets [Line Items]
Useful Life (in years)	10 years	10 years
Gross Carrying Amount	$ 17,400	$ 17,400
Accumulated Amortization	5,148	3,408
Net Carrying Amount	12,252	13,992
Databases and Technology [Member]
Amortized Intangible Assets [Line Items]
Gross Carrying Amount	30,623	27,041
Accumulated Amortization	12,850	8,471
Net Carrying Amount	17,773	18,570
Non-compete Agreements [Member]
Amortized Intangible Assets [Line Items]
Gross Carrying Amount	1,313	1,088
Accumulated Amortization	929	838
Net Carrying Amount	384	250
Other [Member]
Amortized Intangible Assets [Line Items]
Gross Carrying Amount	24,800	24,530
Accumulated Amortization	13,149	9,873
Net Carrying Amount	$ 11,651	$ 14,657
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)	6 years	6 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	$ 100,491	$ 80,102
Franchise Rights [Member]
Indefinite-lived Intangible Assets [Line Items]
Net Carrying Amount	28,556	0
FCC licenses [Member]
Indefinite-lived Intangible Assets [Line Items]
Net Carrying Amount	11,000	18,800
Licensure and Accreditation [Member]
Indefinite-lived Intangible Assets [Line Items]
Net Carrying Amount	$ 150	$ 150