Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Operating activities:
Net income	$ 423.3	$ 164.1
Reconciliation of net income to net cash provided by operating activities:
Depreciation	43.8	40.2
Amortization	53.5	38.9
Stock-based compensation, net of tax benefit	13.4	7.3
Deferred taxes	(8.9)	(1.5)
Gain on sale of discontinued operation, net of tax	(247.6)	0.0
Other operating activities, net	(9.4)	7.9
Changes in assets and liabilities, excluding effects of acquisitions:
Receivables	(194.9)	(167.6)
Inventories	(60.2)	(38.7)
Prepaid expenses and other assets	3.2	6.4
Accounts payable	66.3	71.7
Accrued expenses	(91.1)	(6.8)
Deferred revenues	8.7	13.1
Other long-term liabilities	(2.9)	(0.3)
Net cash (used in) provided by operating activities	(2.8)	134.7
Investing activities:
Proceeds from sale of discontinued operation	754.6	0.0
Capital expenditures	(66.9)	(66.1)
Acquisitions, net of cash acquired	(19.3)	(225.9)
Other investing activities, net	5.7	0.1
Net cash provided by (used in) investing activities	674.1	(291.9)
Financing activities:
Proceeds from revolving credit facility	0.0	263.0
Repayments of revolving credit facility	0.0	(153.0)
Repurchases of common stock	(235.7)	(150.0)
Dividends paid	(45.6)	(45.8)
Withholding tax paid related to stock-based compensation	(9.6)	(8.1)
Proceeds from exercise of stock options	5.0	3.5
Net cash used in financing activities	(285.9)	(90.4)
Effect of foreign currency exchange rate changes on cash and cash equivalents	0.0	2.1
Change in cash and cash equivalents	385.4	(245.5)
Less: change in cash and cash equivalents of discontinued operations	(1.3)	(3.7)
Cash and cash equivalents at beginning of period	378.3	385.3
Cash and cash equivalents at beginning of period	$ 762.4	$ 136.1