Central Merger and Restructuring, Merger and Integration Costs - Additional Information (Details) - USD ($)						12 Months Ended
	Sep. 27, 2016	Mar. 11, 2016	Feb. 19, 2016	Oct. 02, 2012	Sep. 30, 2012	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Settlement reducing cash consideration
Restructuring reserve						$ 2,300,000	$ 5,400,000
Central Merger
Business Acquisition [Line Items]
Interest acquired (as a percentage)				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	$ 27,000,000
Maximum net debt working capital threshold amount (less than)				$ 275,000,000
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
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 (at least)					$ 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
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						18,800,000
Amount paid to former stockholders	2,500,000
Cash consideration paid	24,500,000
Acquisition related costs	800,000					1,200,000	6,900,000	$ 7,200,000
Acquisition related costs, net of tax	$ 500,000
April 30, 2015 | Central Merger
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 | Central Merger
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 | Central Merger
Settlement reducing cash consideration
Net debt working capital at September 30, 2012 as defined in the Merger Agreement					11,300,000
February 19, 2016 | Central Merger
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
Compensation and Payroll Withholdings
Settlement reducing cash consideration
Restructuring reserve						1,800,000	3,600,000
Accrued Expenses
Settlement reducing cash consideration
Restructuring reserve							300,000
Other Noncurrent Liabilities
Settlement reducing cash consideration
Restructuring reserve						$ 500,000	$ 1,500,000