Goodwill and Other Intangible Assets (Other Intangible Assets) (Details 2) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2020	Dec. 31, 2019
Amortized Intangible Assets [Line Items]
Gross Carrying Amount	$ 478,714	$ 452,952
Accumulated Amortization	246,827	219,471
Net Carrying Amount	231,887	233,481
Indefinite-Lived Intangible Assets [Line Items]
Indefinite-Lived Intangible Assets	115,913	140,197
Trade Names and Trademarks [Member]
Indefinite-Lived Intangible Assets [Line Items]
Indefinite-Lived Intangible Assets	82,905	100,491
Franchise Agreements [Member]
Indefinite-Lived Intangible Assets [Line Items]
Indefinite-Lived Intangible Assets	21,858	28,556
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
Student and Customer Relationships [Member]
Amortized Intangible Assets [Line Items]
Gross Carrying Amount	292,300	291,626
Accumulated Amortization	161,020	144,625
Net Carrying Amount	$ 131,280	$ 147,001
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	$ 108,854	$ 87,190
Accumulated Amortization	47,929	42,770
Net Carrying Amount	$ 60,925	$ 44,420
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	10 years	10 years
Gross Carrying Amount	$ 17,400	$ 17,400
Accumulated Amortization	6,019	5,148
Net Carrying Amount	11,381	12,252
Databases and Technology [Member]
Amortized Intangible Assets [Line Items]
Gross Carrying Amount	34,210	30,623
Accumulated Amortization	16,010	12,850
Net Carrying Amount	$ 18,200	$ 17,773
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
Non-compete Agreements [Member]
Amortized Intangible Assets [Line Items]
Gross Carrying Amount	$ 1,150	$ 1,313
Accumulated Amortization	843	929
Net Carrying Amount	$ 307	$ 384
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	$ 24,800	$ 24,800
Accumulated Amortization	15,006	13,149
Net Carrying Amount	$ 9,794	$ 11,651
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