Revenue From Contracts With Customers (Schedule Of Changes In Contract Balances) (Details)	6 Months Ended
	Jun. 30, 2018 USD ($)
Revenue From Contracts With Customer [Abstract]
Revenue recognized that was included in the contract liability balance at the beginning of the period	$ 1,155,677
Cash received, excluding amounts recognized as revenue during the period	(1,157,908)
Net change	(2,231)
Revenue recognized and transferred from contract asset at the beginning of the period	(4,921,794)
Cash received, excluding amounts recognized as revenue during the period	1,670,979
Net change	$ (3,250,815)