Business Combinations - Intangible Assets Acquired (Details) $ in Thousands	Apr. 05, 2017 USD ($)
Community Education Centers
Business Acquisition [Line Items]
Total acquired intangible assets	$ 76,000
Facility management contracts
Business Acquisition [Line Items]
Weighted Average Useful Life (years)	17 years 12 months 100 days
Facility management contracts | Community Education Centers
Business Acquisition [Line Items]
Total acquired intangible assets	$ 75,300
Covenants not to compete
Business Acquisition [Line Items]
Weighted Average Useful Life (years)	1 year
Covenants not to compete | Community Education Centers
Business Acquisition [Line Items]
Total acquired intangible assets	$ 700