Condensed Consolidated Statements of Operations and Comprehensive Income (Unaudited) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jul. 01, 2012	Jul. 03, 2011	Jul. 01, 2012	Jul. 03, 2011
Condensed Consolidated Statements of Operations and Comprehensive Income [Abstract]
Revenues	$ 484,042	$ 536,251	$ 948,333	$ 997,879
Cost of sales	(332,121)	(379,637)	(654,694)	(710,810)
Gross profit	151,921	156,614	293,639	287,069
Selling, general and administrative expenses	(77,931)	(84,380)	(161,157)	(159,316)
Research and development	(15,029)	(14,530)	(29,062)	(28,159)
Amortization of intangibles	(2,570)	(3,347)	(5,805)	(7,026)
Income from equity method investment	1,960	3,855	4,701	7,717
Operating income	58,351	58,212	102,316	100,285
Interest expense	(12,502)	(12,748)	(24,423)	(24,556)
Interest income	211	156	562	315
Income from continuing operations before taxes	46,060	45,620	78,455	76,044
Income tax expense	(3,670)	(10,739)	(11,790)	(19,145)
Income from continuing operations	42,390	34,881	66,665	56,899
Loss from discontinued operations, net of tax		(156)		(284)
Net income	42,390	34,725	66,665	56,615
Weighted average number of common shares and equivalents:
Basic	45,526	47,401	45,720	47,304
Diluted	46,305	48,414	46,623	48,372
Basic income (loss) per share:
Continuing operations	$ 0.93	$ 0.73	$ 1.46	$ 1.20
Discontinued operations				$ (0.01)
Net income	$ 0.93	$ 0.73	$ 1.46	$ 1.19
Diluted income (loss) per share:
Continuing operations	$ 0.92	$ 0.72	$ 1.43	$ 1.18
Discontinued operations				$ (0.01)
Net income	$ 0.92	$ 0.72	$ 1.43	$ 1.17
Comprehensive income	$ 14,152	$ 42,326	$ 49,053	$ 86,973
Dividends declared per share	$ 0.05	$ 0.05	$ 0.10	$ 0.10