Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012		Mar. 31, 2011
Cash flow from operating activities:
Net income	$ 12.9		$ 12.2
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Depreciation, depletion, and amortization	10.6		9.4
Other non-cash charges	4.0		1.9
Changes in assets and liabilities, net of effects of acquisitions:
Decrease (increase) in current assets	2.8		(18.3)
Decrease (increase) in noncurrent assets	(2.0)		(0.7)
Increase (decrease) in current liabilities	(8.8)		5.2
Increase (decrease) in noncurrent liabilities	1.1		0.6
Net cash provided by (used in) operating activities	20.6		10.3
Cash flow from investing activities:
Capital expenditures	(16.6)		(10.4)
Proceeds from sale of joint ventures	0.6
Other	0.7		0.1
Net cash (used in) investing activities	(15.3)		(10.3)
Cash flow from financing activities:
Net change in outstanding debt	(10.1)		(3.6)
Proceeds from sales of treasury stock	3.6		2.8
Dividends	(5.7)		(5.7)
Excess tax benefits from stock-based compensation	0.1		0.2
Net cash provided by (used in) financing activities	(12.1)		(6.3)
Effect of foreign currency rate changes on cash			0.2
Net increase (decrease) in cash and cash equivalents	(6.8)		(6.1)
Cash and cash equivalents at beginning of period	23.7	[1]	27.3
Cash and cash equivalents at end of period	$ 16.9		$ 21.2

[1] *Condensed from audited financial statements.