CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Cash flows from operating activities:
Net income	$ 60.7	$ 64.7
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	42.1	42.6
Amortization	2.1	2.3
Stock-based compensation	20.8	8.9
Other non-cash items, net	(1.6)	(1.9)
Changes in assets and liabilities	(48.5)	(43.6)
Net cash provided by operating activities	75.6	73.0
Cash flows from investing activities:
Capital expenditures	(57.1)	(56.2)
Purchases of short-term investments	0.0	(9.3)
Sales and maturities of short-term investments	0.0	8.3
Other, net	1.0	0.2
Net cash used in investing activities	(56.1)	(57.0)
Cash flows from financing activities:
Borrowings under revolving credit agreements	43.6	182.9
Repayments under revolving credit agreements	(43.6)	(192.9)
Repayments of long-term debt	(1.2)	(1.1)
Dividend payments	(15.8)	(14.1)
Excess tax benefit from employee stock plans	3.5	3.7
Shares repurchased for employee tax withholdings	(5.6)	(4.1)
Proceeds from exercise of stock options and stock appreciation rights	8.2	5.2
Employee stock purchase plan contributions	1.5	1.5
Contingent consideration payments	(0.1)	(0.1)
Net cash used in financing activities	(9.5)	(19.0)
Effect of exchange rates on cash	(13.3)	(0.3)
Net decrease in cash and cash equivalents	(3.3)	(3.3)
Cash and cash equivalents at beginning of period	255.3	230.0
Cash and cash equivalents at end of period	$ 252.0	$ 226.7