Geographic Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 27, 2013	Jun. 28, 2013	Mar. 29, 2013	Dec. 31, 2012	Sep. 28, 2012	Jun. 29, 2012	Mar. 30, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Segment Reporting Information [Line Items]
Sales	$ 87,707	$ 85,484	$ 85,307	$ 83,114	$ 66,413	$ 69,520	$ 70,379	$ 65,186	$ 341,612	$ 271,498	$ 304,296
Percentage of Total									100.00%	100.00%	100.00%
UNITED STATES
Segment Reporting Information [Line Items]
Sales									115,351	86,310	102,792
Percentage of Total									33.80%	31.80%	33.80%
GERMANY
Segment Reporting Information [Line Items]
Sales									57,873	36,554	43,805
Percentage of Total									16.90%	13.40%	14.40%
Rest Of Europe
Segment Reporting Information [Line Items]
Sales									51,349	45,261	47,832
Percentage of Total									15.00%	16.70%	15.70%
Asia-Pacific
Segment Reporting Information [Line Items]
Sales									75,016	67,717	72,201
Percentage of Total									22.00%	24.90%	23.70%
JAPAN
Segment Reporting Information [Line Items]
Sales									29,689	27,808	30,597
Percentage of Total									8.70%	10.20%	10.10%
Other Country
Segment Reporting Information [Line Items]
Sales									$ 12,334	$ 7,848	$ 7,069
Percentage of Total									3.60%	3.00%	2.30%