Unconsolidated Affiliate (Details) - USD ($)	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Investment in unconsolidated affiliates
Equity method investment ownership interest (percent)	50.00%
Investment in unconsolidated affiliate	$ 110,600,000		$ 103,200,000
Equity in earnings of unconsolidated affiliate	6,900,000	$ 6,200,000
Summary of Statement of Operations information:
Net sales	64,000,000	77,200,000
Costs and expenses applicable to net sales	48,200,000	64,700,000
Income before income taxes	13,900,000	12,600,000
Net income	13,800,000	12,300,000
Grace sales of catalysts to ART	56,500,000	54,200,000
Charges for fixed costs, research and development and selling, general and administrative services to ART	6,200,000	$ 5,900,000
Grace
Summary of Statement of Operations information:
Line of credit facility, maximum provided by Grace and Chevron each	$ 15,000,000.0
Commitment fee on credit facility (as a percent)	0.10%
Credit facility amount outstanding	$ 0
Chevron
Summary of Statement of Operations information:
Line of credit facility, maximum provided by Grace and Chevron each	$ 15,000,000.0
Commitment fee on credit facility (as a percent)	0.10%
Credit facility amount outstanding			$ 0