Consolidated Statements Of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 27, 2015	Sep. 28, 2014	Sep. 27, 2015	Sep. 28, 2014
Income Statement [Abstract]
Net revenues	$ 145,930	$ 160,595	$ 422,022	$ 478,926
Cost of revenues	87,204	89,630	245,262	273,168
Gross profit	58,726	70,965	176,760	205,758
Selling, general, and administrative expenses	48,923	55,480	152,120	165,195
Research and development	5,281	3,971	14,745	11,663
Restructuring expense	(5)	459	1,583	2,692
Litigation matters	6,584	0	15,564	0
Acquisition costs	15	291	135	291
Other operating income	0	0	(493)	0
Operating (loss) income	(2,072)	10,764	(6,894)	25,917
Interest income	179	323	638	875
Interest expense	971	1,062	2,899	3,517
Other gain (loss), net	852	10	364	(518)
(Loss) earnings before income taxes	(2,012)	10,035	(8,791)	22,757
Income tax expense	1,979	14,110	7,251	17,107
Net (loss) earnings	$ (3,991)	$ (4,075)	$ (16,042)	$ 5,650
Net (loss) earnings per common share:
Basic (loss) earnings per share (USD per share)	$ (0.09)	$ (0.10)	$ (0.37)	$ 0.13
Diluted (loss) earnings per share (USD per share)	(0.09)	(0.10)	(0.37)	0.13
Dividends declared per share (USD per share)	$ 0	$ 0	$ 0.50	$ 0