Unconsolidated Affiliates (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Equity Method Investments and Joint Ventures [Abstract]
Equity method investment, ownership interest	50.00%
Investment in unconsolidated affiliate	$ 96.2	$ 85.5
Equity in earnings of unconsolidated affiliates	22.9	18.5	15.2
ART's assets, liabilities and results of operations:
Current assets	187.9	136.7
Noncurrent assets	62.5	65.9
Total assets	250.4	202.6
Current liabilities	62.6	37.8
Noncurrent liabilities	0.6	0.1
Total liabilities	63.2	37.9
Net sales	377.6	325.0	339.0
Costs and expenses applicable to net sales	318.4	276.0	296.3
Income before income taxes	46.6	38.9	32.8
Net income	45.6	37.8	31.2
Related party transactions:
Grace sales of catalysts to ART	232.0	206.9	171.4
Charges for fixed costs, research and development and selling, general and administrative services to ART	28.8	28.5	27.8
Schedule of Investments [Line Items]
Commitment fee on credit facility	0.10%
W R Grace & Co. [Member]
Schedule of Investments [Line Items]
Line of credit facility, maximum provided by Grace and Chevron each	$ 15