Condensed Consolidated Statements Of Cash Flows - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2017	Jul. 01, 2016
Cash flow from operating activities:
Net Income	$ 100.4	$ 55.3
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation expense	17.7	18.8
Amortization expense	69.1	79.9
Provision for doubtful accounts	0.9	2.4
Deferred income taxes	(0.2)	0.5
Stock-based compensation	28.9	26.7
Income from equity method investments	(14.1)	(8.7)
Divestiture gain, net	(8.0)	(2.7)
Provision for excess and obsolete inventories	1.6	8.8
Other non-cash items	(1.6)	3.0
Decrease (increase) in assets:
Accounts receivable	(31.0)	(18.2)
Other receivables	2.8	(1.5)
Inventories	(1.8)	11.2
Other current and non-current assets	(14.0)	(7.8)
Increase (decrease) in liabilities:
Accounts payable	22.0	6.4
Accrued compensation and benefits	14.1	2.2
Deferred revenue	49.4	53.8
Accrued warranty	0.1	(0.7)
Other liabilities	12.4	(33.8)
Net cash provided by operating activities	248.7	195.6
Cash flow from investing activities:
Acquisitions of businesses, net of cash acquired	(129.8)	(20.0)
Acquisitions of property and equipment	(15.6)	(12.2)
Purchases of equity method investments	0.0	(1.5)
Purchases of short-term investments	(137.6)	0.0
Proceeds from maturities of short-term investments	56.8	0.0
Proceeds from sales of short-term investments	90.6	0.0
Net proceeds from sales of businesses	20.1	10.7
Dividends received from equity method investments	5.0	10.7
Other	0.2	(0.3)
Net cash used in investing activities	(110.3)	(12.6)
Cash flow from financing activities:
Issuance of common stock, net of tax withholdings	49.8	25.0
Repurchases and retirement of common stock	(20.4)	(88.3)
Proceeds from debt and revolving credit lines	340.0	202.0
Payments on debt and revolving credit lines	(350.1)	(207.0)
Net cash provided by (used in) financing activities	19.3	(68.3)
Effect of exchange rate changes on cash and cash equivalents	11.1	1.2
Net increase in cash and cash equivalents	168.8	115.9
Cash and cash equivalents - beginning of period	216.1	116.0
Cash and cash equivalents - end of period	$ 384.9	$ 231.9