Basis of Presentation of Interim Financial Information - Initial Public Offering (Details) - USD ($) $ / shares in Units, shares in Thousands	1 Months Ended	3 Months Ended	6 Months Ended
	May 31, 2015	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Initial Public Offering
IPO related costs incurred but not yet paid				$ 3,426,000
Equity-based compensation			$ 13,349,000	74,997,000
Loss on extinguishment of debt		$ 638,000		638,000
Transaction Advisory Fee | Vestar
Initial Public Offering
Transaction advisory fee				$ 8,500,000
IPO
Initial Public Offering
Equity-based compensation	$ 70,400,000
IPO | Term Loan
Initial Public Offering
Loss on extinguishment of debt	638,000
Partial debt repayment	223,000,000
IPO | Transaction Advisory Fee | Vestar
Initial Public Offering
Transaction advisory fee	$ 8,500,000
IPO | Common
Initial Public Offering
Shares issued in offering	10,235
Share price (in dollars per share)	$ 25.00
Proceeds from the issuance of common stock in initial public offering, net of fees	$ 234,400,000
IPO, excluding Underwriters' Option | Common
Initial Public Offering
Shares issued in offering	8,900
Underwriters' Option | Common
Initial Public Offering
Shares issued in offering	1,335