Commitments and Contingencies (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2012 sqft	Sep. 30, 2011	Sep. 30, 2012 sqft	Sep. 30, 2011
Product Warranty [Abstract]
Period of warranty			12 months
Change in warranty accrual [Roll Forward]
Beginning accrued warranty and related costs	$ 740,000	$ 877,000	$ 1,003,000	$ 740,000
Charges/(benefit) to cost of revenue	(135,000)	(139,000)	(637,000)	(410,000)
Actual warranty expenditures	92,000	74,000	331,000	482,000
Ending accrued warranty and related costs	697,000	812,000	697,000	812,000
Contractual Obligations [Abstract]
Area of property under long-term operating lease (in square feet)	27,760		27,760
Period of operating lease	7 years		7 years
Period to be lapsed for cancelling lease	5 years		5 years
Percentage of annual rent to be paid for cancelling lease (in hundredths)	50.00%		50.00%
Term of royalty agreement	8 years		8 years
Aggregate amount payable towards royalty	7,000,000		7,000,000
Outstanding contractual obligations [Abstract]
Total	5,553,000		5,553,000
Less than 1 year	1,308,000		1,308,000
1-3 years	2,264,000		2,264,000
3-5 years	1,262,000		1,262,000
More than 5 years	719,000		719,000
Operating leases [Member]
Outstanding contractual obligations [Abstract]
Total	1,114,000		1,114,000
Less than 1 year	395,000		395,000
1-3 years	664,000		664,000
3-5 years	55,000		55,000
More than 5 years	0		0
Royalty agreement [Member]
Outstanding contractual obligations [Abstract]
Total	4,439,000		4,439,000
Less than 1 year	913,000		913,000
1-3 years	1,600,000		1,600,000
3-5 years	1,207,000		1,207,000
More than 5 years	$ 719,000		$ 719,000