Goodwill and Other Intangible Assets (Other Intangible Assets) (Details 2) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2022	Dec. 31, 2021
Amortized Intangible Assets [Line Items]
Gross Carrying Amount	$ 577,744	$ 581,877
Accumulated Amortization	375,484	334,757
Net Carrying Amount	202,260	247,120
Indefinite-Lived Intangible Assets [Line Items]
Indefinite-Lived Intangible Assets	174,915	142,180
Trade Names and Trademarks [Member]
Indefinite-Lived Intangible Assets [Line Items]
Indefinite-Lived Intangible Assets	77,887	86,972
Franchise Agreements [Member]
Indefinite-Lived Intangible Assets [Line Items]
Indefinite-Lived Intangible Assets	85,858	44,058
FCC licenses [Member]
Indefinite-Lived Intangible Assets [Line Items]
Indefinite-Lived Intangible Assets	11,000	11,000
Licensure and Accreditation [Member]
Indefinite-Lived Intangible Assets [Line Items]
Indefinite-Lived Intangible Assets	150	150
Other [Member]
Indefinite-Lived Intangible Assets [Line Items]
Indefinite-Lived Intangible Assets	20	0
Student and Customer Relationships [Member]
Amortized Intangible Assets [Line Items]
Gross Carrying Amount	296,743	300,027
Accumulated Amortization	223,485	206,714
Net Carrying Amount	$ 73,258	$ 93,313
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	$ 157,303	$ 158,365
Accumulated Amortization	78,189	68,113
Net Carrying Amount	$ 79,114	$ 90,252
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	15 years	15 years
Databases and Technology [Member]
Amortized Intangible Assets [Line Items]
Gross Carrying Amount	$ 35,848	$ 36,585
Accumulated Amortization	30,454	26,464
Net Carrying Amount	$ 5,394	$ 10,121
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	6 years	6 years
Network Affiliation Agreements [Member]
Amortized Intangible Assets [Line Items]
Useful Life	10 years	10 years
Gross Carrying Amount	$ 17,400	$ 17,400
Accumulated Amortization	9,933	8,628
Net Carrying Amount	7,467	8,772
Non-compete Agreements [Member]
Amortized Intangible Assets [Line Items]
Gross Carrying Amount	1,000	1,000
Accumulated Amortization	994	991
Net Carrying Amount	$ 6	$ 9
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	$ 69,450	$ 68,500
Accumulated Amortization	32,429	23,847
Net Carrying Amount	$ 37,021	$ 44,653
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