Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Operating activities
Net income	$ 365.5	$ 250.1	$ 319.7
Reconciliation of net income to cash flows provided by operating activities:
Depreciation	84.9	75.1	73.5
Amortization	84.2	62.7	55.8
Impairment charges	0.0	141.5	0.0
Stock-based compensation, net of tax benefit	13.2	(2.6)	2.7
Deferred taxes	(58.5)	(25.0)	(15.8)
Other operating activities, net	13.9	(6.0)	(1.3)
Changes in assets and liabilities, excluding effects of acquisitions:
Receivables	(53.9)	0.3	(11.8)
Inventories	(48.5)	(12.2)	23.0
Prepaid expenses and other assets	(20.1)	(9.2)	6.7
Accounts payable	42.7	21.6	(2.9)
Accrued expenses	20.6	23.1	62.9
Deferred revenues	19.3	11.7	15.5
Other long-term liabilities	(4.6)	0.1	1.2
Net cash provided by operating activities	458.7	531.2	529.2
Investing activities
Acquisitions, net of cash acquired	(934.3)	(185.5)	(598.9)
Capital expenditures	(159.9)	(108.8)	(72.1)
Other investing activities, net	(0.1)	0.9	0.2
Net cash used in investing activities	(1,094.3)	(293.4)	(670.8)
Financing activities
Proceeds from revolving credit facility	1,189.0	0.0	0.0
Repayments of revolving credit facility	(1,189.0)	0.0	0.0
Proceeds from notes	997.2	0.0	0.0
Repayments of notes	0.0	(150.0)	(1.5)
Repurchases of common stock	(268.4)	(75.0)	(137.2)
Dividends paid	(92.1)	(84.5)	(72.3)
Financing costs	(8.3)	0.0	0.0
Proceeds from exercise of stock options, net	(1.2)	48.4	39.4
Other financing activities, net	0.0	0.0	(1.4)
Net cash provided (used) in financing activities	627.2	(261.1)	(173.0)
Effect of foreign currency exchange rate changes on cash and cash equivalents	2.7	(2.1)	(5.5)
Change in cash and cash equivalents	(5.7)	(25.4)	(320.1)
Cash and cash equivalents
Beginning of period	385.3	410.7	730.8
End of period	$ 379.6	$ 385.3	$ 410.7