Goodwill and Intangible Assets - Intangibles (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Subject to amortization
Accumulated Amortization	$ (9,223)
Total
Intangible assets, gross	351,700
Intangible assets, net	342,477	$ 7,260
Trade names
Not Subject to amortization
Net	185,700	7,300
Student relationships
Subject to amortization
Gross Carrying Amount	166,000
Accumulated Amortization	(9,223)
Net	$ 156,777	$ 0