Goodwill and Other Intangible Assets - Summary of Identifiable Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Subject to amortization:
Accumulated Amortization	$ (102,044)	$ (110,755)
Total	25,429	35,779
Not subject to amortization:
Tradenames	1,126,244	1,167,302
Gross Carrying Amount, Total	1,253,717	1,313,836
Net Carrying Amount, Total	1,151,673	1,203,081
Tradenames
Not subject to amortization:
Tradenames	1,126,244	1,167,302
Student rosters
Subject to amortization:
Gross Carrying Amount	69,540	80,564
Accumulated Amortization	(69,253)	(79,005)
Total	$ 287	$ 1,559
Not subject to amortization:
Weighted Average Amortization Period (Yrs)	10 months 24 days	1 year 10 months 24 days
Other
Subject to amortization:
Gross Carrying Amount	$ 57,933	$ 65,970
Accumulated Amortization	(32,791)	(31,750)
Total	$ 25,142	$ 34,220
Not subject to amortization:
Weighted Average Amortization Period (Yrs)	11 years 2 months 24 days	11 years 4 months 24 days