Goodwill and Other Intangible Assets (Other Intangible Assets) (Details 2) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Amortized Intangible Assets [Line Items]
Gross Carrying Amount	$ 581,877	$ 481,950
Accumulated Amortization	334,757	277,304
Net Carrying Amount	247,120	204,646
Indefinite-lived Intangible Assets [Line Items]
Net Carrying Amount	142,180	120,437
Student and Customer Relationships [Member]
Amortized Intangible Assets [Line Items]
Gross Carrying Amount	300,027	294,077
Accumulated Amortization	206,714	178,075
Net Carrying Amount	93,313	116,002
Trade Names and Trademarks [Member]
Amortized Intangible Assets [Line Items]
Gross Carrying Amount	158,365	109,809
Accumulated Amortization	68,113	54,766
Net Carrying Amount	$ 90,252	$ 55,043
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	8,628	6,888
Net Carrying Amount	8,772	10,512
Databases and Technology [Member]
Amortized Intangible Assets [Line Items]
Gross Carrying Amount	36,585	34,864
Accumulated Amortization	26,464	19,924
Net Carrying Amount	10,121	14,940
Non-compete Agreements [Member]
Amortized Intangible Assets [Line Items]
Gross Carrying Amount	1,000	1,000
Accumulated Amortization	991	937
Net Carrying Amount	9	63
Other [Member]
Amortized Intangible Assets [Line Items]
Gross Carrying Amount	68,500	24,800
Accumulated Amortization	23,847	16,714
Net Carrying Amount	$ 44,653	$ 8,086
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)	15 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)	15 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	$ 86,972	$ 87,429
Franchise Rights [Member]
Indefinite-lived Intangible Assets [Line Items]
Net Carrying Amount	44,058	21,858
FCC licenses [Member]
Indefinite-lived Intangible Assets [Line Items]
Net Carrying Amount	11,000	11,000
Licensure and Accreditation [Member]
Indefinite-lived Intangible Assets [Line Items]
Net Carrying Amount	$ 150	$ 150