Condensed Consolidated Statements Of Cash Flows - USD ($) $ in Millions		3 Months Ended
		Mar. 30, 2018		Mar. 31, 2017
Cash flow from operating activities:
Net income		$ 58.7		$ 49.8	[1],[2],[3]
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation expense		8.5		8.9	[3]
Amortization expense		40.5		33.3	[3],[4]
Stock-based compensation		17.4		13.7	[3],[4]
Income from equity method investments		(0.1)		(2.7)	[3]
Other non-cash items		(7.4)		(9.7)	[3]
Decrease (increase) in assets:
Accounts receivable		(29.4)		(34.0)	[3]
Inventories		(21.7)		(2.4)	[3]
Other current and non-current assets		(10.6)		(4.7)	[3]
Increase (decrease) in liabilities:
Accounts payable		11.1		3.5	[3]
Accrued compensation and benefits		(41.6)		(14.8)	[3]
Deferred revenue		69.6		53.3	[3]
Other liabilities		(12.1)		9.8	[3]
Net cash provided by operating activities		82.9		104.0	[3]
Cash flow from investing activities:
Acquisitions of businesses, net of cash acquired		(518.7)		(78.5)	[3]
Acquisitions of property and equipment		(18.2)		(5.7)	[3]
Purchases of short-term investments		(24.0)		(59.0)	[3]
Proceeds from maturities of short-term investments		6.2		24.4	[3]
Proceeds from sales of short-term investments		196.8		3.9	[3]
Other		4.4		19.6	[3]
Net cash used in investing activities		(353.5)		(95.3)	[3]
Cash flow from financing activities:
Issuance of common stock, net of tax withholdings		25.3		39.6	[3]
Repurchases of common stock		(53.0)		(14.2)	[3]
Proceeds from debt and revolving credit lines		591.0		252.0	[3]
Payments on debt and revolving credit lines		(383.0)		(226.1)	[3]
Other	[3]			(0.3)
Net cash provided by financing activities		180.3		51.0	[3]
Effect of exchange rate changes on cash and cash equivalents		6.3		5.0	[3]
Net increase (decrease) in cash and cash equivalents		(84.0)		64.7	[3]
Consolidated operating income		64.2		54.7	[1],[4]
Cash and cash equivalents - beginning of period		358.5	[5]	216.1	[3]
Cash and cash equivalents - end of period		$ 274.5		$ 280.8	[3]

[1] See Note 2 for a summary of adjustments

[2] See Note 2 for a summary of adjustments

[3] See Note 2 for a summary of adjustments

[4] See Note 2 for a summary of adjustments

[5] See Note 2 for a summary of adjustments