CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
Cash flows from operating activities:
Net income	$ 61.9	$ 44.8
Depreciation	39.1	35.2
Amortization	2.1	2.2
Loss on debt extinguishment	0.2	11.6
Asset impairment charges	0	3.8
Other non-cash items, net	7.7	4.7
Changes in assets and liabilities	(12.6)	(36.3)
Net cash provided by operating activities	98.4	66.0
Cash flows from investing activities:
Capital expenditures	(83.8)	(69.4)
Purchases of short-term investments	(8.8)	(26.0)
Sales and maturities of short-term investments	13.7	27.3
Other, net	(3.0)	0.3
Net cash used in investing activities	(81.9)	(67.8)
Cash flows from financing activities:
Borrowings under revolving credit agreements, net	6.7	198.6
Repayments of long-term debt	(29.3)	(165.7)
Issuance of long-term debt	43.3	0
Debt issuance costs	0	(6.2)
Dividend payments	(13.1)	(12.2)
Excess tax benefit from employee stock plans	1.1	2.1
Shares repurchased for employee tax withholdings	(5.2)	(2.2)
Proceeds from stock option exercises	10.7	2.9
Employee stock purchase plan contributions	1.1	1.1
Net cash provided by financing activities	15.3	18.4
Effect of exchange rates on cash	(3.1)	(1.4)
Net increase in cash and cash equivalents	28.7	15.2
Cash, including cash equivalents at beginning of period	161.9	91.8
Cash, including cash equivalents at end of period	$ 190.6	$ 107.0