Acquisition - Additional Information (Details) - Central Merger - USD ($)					6 Months Ended	12 Months Ended
	Mar. 11, 2016	Feb. 19, 2016	Oct. 02, 2012	Sep. 30, 2012	Jun. 30, 2016	Dec. 31, 2015
Acquisitions
Interest acquired (as a percent)			100.00%
Common stock issued (in shares)			6,161,332
Assumption of debt, net of cash acquired			$ 217,700,000
Cash consideration payable in three years from the acquisition date, pursuant to the Merger Agreement and prior to Central Net Debt Working Capital and indemnification of certain defined adverse consequences, net			27,000,000	$ 27,000,000
Maximum net debt working capital threshold amount (less than)			$ 275,000,000.0
Period after which contingent cash consideration to be paid			3 years
Threshold of net debt working capital, pursuant to the Merger Agreement				$ 285,000,000.0
Price of share at which former stockholders of acquiree can elect to pay applicable amount (in dollars per share)				$ 23.64
Minimum cash consideration to cover capped indemnities				$ 17,000,000.0
Settlement reducing cash consideration
Net debt working capital at September 30, 2012 as defined in the Merger Agreement				296,300,000
Reduction of cash consideration payable				11,300,000
Indemnification of certain defined adverse consequences, net	$ 26,500,000	$ 24,900,000		23,400,000
Estimated amount in cash consideration payable for sellers indemnification for structural repair cost					$ 700,000
Indemnification of cost pursuant to merger agreement					80.00%
Total of estimated amount in cash consideration payable for sellers indemnification for structural repair cost					$ 900,000
Net debt working capital allowable claims		1,500,000
Indemnification of certain defined adverse consequences incurred through September 30, 2015, net		1,500,000
Net debt working capital expense						$ 1,600,000
Net debt working capital expense, net of tax						$ 900,000
Net debt working capital disallowable claims		$ 1,600,000
Additional indemnity claims	$ 1,600,000				7,700,000
Reduction due to net debt working capital					6,600,000
Reduction due to indemnified claims					$ 18,600,000
April 30, 2015
Settlement reducing cash consideration
Net debt working capital at September 30, 2012 as defined in the Merger Agreement				270,800,000
Net debt capital difference as of September 30, 2012 below the lower threshold				4,200,000
September 21, 2015
Settlement reducing cash consideration
Net debt working capital at September 30, 2012 as defined in the Merger Agreement				278,000,000
Net debt capital difference as of September 30, 2012 above the lower threshold				3,000,000
October 1, 2015
Settlement reducing cash consideration
Net debt working capital at September 30, 2012 as defined in the Merger Agreement				11,300,000
February 19, 2016
Settlement reducing cash consideration
Net debt working capital at September 30, 2012 as defined in the Merger Agreement				291,600,000
Reduction of cash consideration payable				$ 6,600,000