Condensed Consolidated Statements of Cash Flows (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011
Cash provided by operating activities:
Net income	$ 206.3	$ 236.5
Non-cash charges (credits) to net income:
Write-off of impaired assets	6
Depreciation and amortization	107	103
Changes in working capital:
Accounts receivable and prepaid items	(48)	(48)
Inventories	(17)	(169)
Accounts payable and accrued liabilities	(38)	(49)
Decrease in margin accounts	56	6
Other	46	22
Cash provided by operating activities	318	102
Cash used for investing activities:
Capital expenditures, net of proceeds on disposals	(128)	(89)
Payment for acquisition		(15)
Cash used for investing activities	(128)	(104)
Cash used for financing activities:
Proceeds from borrowings	20	28
Payments on debt	(131)	(44)
Repurchases of common stock	(16)	(3)
Issuances of common stock	13	13
Dividends paid (including to non-controlling interests)	(33)	(24)
Excess tax benefit on share-based compensation	1	2
Cash used for financing activities	(146)	(28)
Effect of foreign exchange rate changes on cash	(5)	1
Increase (decrease) in cash and cash equivalents	39	(29)
Cash and cash equivalents, beginning of period	401	302
Cash and cash equivalents, end of period	$ 440	$ 273