Goodwill and Other Intangible Assets (Details) (USD $)	12 Months Ended
	Dec. 31, 2011 Y	Jan. 01, 2011	Jan. 02, 2010
Goodwill
Balance at the beginning of the period	$ 112,296,000	$ 105,109,000
Additions due to business combinations	4,097,000	7,187,000
Adjustments	(904,000)
Balance at the end of the period	115,489,000	112,296,000	105,109,000
Gross carrying amount and accumulated amortization of other intangible assets
Weighted-Average Amortization Period (in years)	9.4
Intangible assets subject to amortization, Gross Amount	82,010,000	70,578,000
Intangible assets subject to amortization, Accumulated Amortization	(30,955,000)	(26,806,000)
Total intangible assets, Gross Amount	90,960,000	80,048,000
Intangible assets acquired in acquisition of Spectra Linear	18,000,000
Fully amortized intangible assets, gross	2,900,000
Impaired intangible assets, gross	4,200,000
Unamortized intangible assets, net	1,300,000
Impairment of intangible assets	1,300,000
Amortization expense related to intangible assets	9,900,000	7,500,000	7,800,000
Estimated aggregate amortization expense for intangible assets subject to amortization for each of the five succeeding fiscal years
2012	9,056,000
2013	7,680,000
2014	6,840,000
2015	6,448,000
2016	5,716,000
In-process research and development
Gross carrying amount and accumulated amortization of other intangible assets
Intangible assets not subject to amortization, Gross and Net Amount	8,950,000	9,470,000
Core and developed technology
Gross carrying amount and accumulated amortization of other intangible assets
Weighted-Average Amortization Period (in years)	9.4
Intangible assets subject to amortization, Gross Amount	79,500,000	64,270,000
Intangible assets subject to amortization, Accumulated Amortization	(30,432,000)	(22,383,000)
Customer relationships
Gross carrying amount and accumulated amortization of other intangible assets
Weighted-Average Amortization Period (in years)	9.9
Intangible assets subject to amortization, Gross Amount	2,510,000	3,410,000
Intangible assets subject to amortization, Accumulated Amortization	(523,000)	(1,766,000)
Patents
Gross carrying amount and accumulated amortization of other intangible assets
Intangible assets subject to amortization, Gross Amount		2,898,000
Intangible assets subject to amortization, Accumulated Amortization		$ (2,657,000)