Product Warranty Provisions (Schedule Of Accrued Warranty) (Details) (USD $)	3 Months Ended	12 Months Ended
	Mar. 31, 2013	Dec. 31, 2012
Product Warrantie Provisions [Abstract]
Warranty accrual, beginning of the fiscal year	$ 653,473	$ 691,832
Warranty expense incurred	19,839	650,367
Payments made	(68,924)	(688,726)
Warranty accrual, end of the fiscal year	$ 604,388	$ 653,473