Accrued Liabilities (Details) (USD $) In Millions, unless otherwise specified	39 Months Ended
	Mar. 31, 2013	Jun. 30, 2013		Dec. 31, 2012
Accrued liabilities
Accrued sales discounts		$ 27.8	[1]	$ 36.2	[1]
Accrued benefits		16.4		21.5
Other taxes payable		11.5		10.9
Other		19.3		22.6
Total		75.0		91.2
Payment of Accrual for Sale Volume Discount Payable Current	11.8
Gain (Loss) on Payment of Accrual for Sales Volume Discount Payable Current	0.6
Haverhill [Member]
Accrued liabilities
Accrued sales discounts				$ 12.4

[1] At December 31, 2012, we had $12.4 million accrued related to sales discounts to be paid to our customer at our Haverhill facility. During the first quarter of 2013, we settled this obligation for $11.8 million which resulted in a gain of $0.6 million. This gain is recorded in sales and other operating revenue on our consolidated statement of income.