Contingencies (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Site Contingency [Line Items]
Accrual for environmental loss contingencies	$ 9,700,000	$ 6,900,000
Loss contingency, range of possible loss, minimum	0
Loss contingency, range of possible loss, maximum	3,900,000
Other noncurrent assets
Site Contingency [Line Items]
Receivable from a third party	800,000	1,600,000
Picton, Ontario Facility
Site Contingency [Line Items]
Increase due to charge to establish a liability for environmental investigation and remediation activities	$ 3,300,000	$ 2,300,000