Deferred Revenue (Schedule Of Deferred Revenue) (Details) (USD $)	Jun. 30, 2012	Dec. 31, 2011
Deferred Revenue Arrangement [Line Items]
Deferred revenue	$ 8,302,233	$ 8,855,019
Less: Long-term deferred revenue	(766,860)	(634,713)
Total current deferred revenue	7,535,373	8,220,306
Product Shipped, Revenue Deferred [Member]
Deferred Revenue Arrangement [Line Items]
Deferred revenue	1,595,106	2,001,160
Customer Deposits [Member]
Deferred Revenue Arrangement [Line Items]
Deferred revenue	447,700	1,156,900
Deferred Service And License Fees [Member]
Deferred Revenue Arrangement [Line Items]
Deferred revenue	$ 6,259,427	$ 5,696,959