Acquisition of the New Business - Description (Details) $ in Thousands		3 Months Ended		6 Months Ended
	Nov. 02, 2016 USD ($)	Jun. 30, 2017 USD ($) employee	Jun. 30, 2016 USD ($)	Jun. 30, 2017 USD ($) employee	Jun. 30, 2016 USD ($)
Purchase of assets and business
Additional payment for acquisition				$ 1,233
Operating results
Net sales		$ 152,998	$ 132,597	295,701	$ 252,796
Income from operations		11,021	$ 12,171	$ 16,919	$ 20,634
Activated Carbon and Filter Aid Business (New Business)
Purchase of assets and business
Cash paid for acquisition	$ 158,658
Additional payment for acquisition		$ 1,200
Activated Carbon and Filter Aid Business (New Business) | Previously reported
Purchase of assets and business
Cash paid for acquisition	$ 157,400
Activated Carbon and Filter Aid Business (New Business)
Purchase of assets and business
Number of employees | employee		300		300
Operating results
Net sales		$ 24,400		$ 48,600
Income from operations		$ 1,700		$ 2,400