Condensed Consolidated Income Statements - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 02, 2017	Jul. 03, 2016	Jul. 02, 2017	Jul. 03, 2016
Product revenue	$ 355,001	$ 356,975	$ 688,715	$ 681,328
Service revenue	191,961	179,267	372,362	352,930
Total revenue	546,962	536,242	1,061,077	1,034,258
Cost of product revenue	173,139	172,706	336,308	327,534
Cost of service revenue	116,320	109,982	227,655	218,084
Total cost of revenue	289,459	282,688	563,963	545,618
Selling, general and administrative expenses	147,944	150,952	293,037	295,490
Research and development expenses	33,562	31,868	66,850	61,839
Restructuring and contract termination charges, net	0	4,468	9,651	4,468
Operating income from continuing operations	75,997	66,266	127,576	126,843
Interest and other expense, net	5,205	5,393	16,801	16,479
Income from continuing operations before income taxes	70,792	60,873	110,775	110,364
Provision for income taxes	8,066	3,117	11,987	10,864
Income from continuing operations	62,726	57,756	98,788	99,500
(Loss) income from discontinued operations before income taxes	(3,109)	4,927	650	13,117
Gain (loss) on disposition of discontinued operations before income taxes	180,377	(8)	180,377	(11)
Provision for (benefit from) income taxes on discontinued operations and dispositions	35,925	(1,182)	37,143	1,283
Income from discontinued operations and dispositions	141,343	6,101	143,884	11,823
Net income	$ 204,069	$ 63,857	$ 242,672	$ 111,323
Basic earnings (loss) per share:
Income (loss) from continuing operations (per share)	$ 0.57	$ 0.53	$ 0.90	$ 0.91
Gain (loss) on discontinued operations and dispositions (per share)	1.29	0.06	1.31	0.11
Net income (per share)	1.86	0.59	2.21	1.01
Diluted earnings (loss) per share:
Income (loss) from continuing operations (per share)	0.57	0.53	0.89	0.90
Gain (loss) on discontinued operations and dispositions (per share)	1.28	0.06	1.30	0.11
Net income (per share)	$ 1.84	$ 0.58	$ 2.20	$ 1.01
Weighted average shares of common stock outstanding:
Basic (in shares)	109,894	108,970	109,681	109,690
Diluted (in shares)	110,762	109,844	110,484	110,520
Cash dividends per common share	$ 0.07	$ 0.07	$ 0.14	$ 0.14