Summary Of Significant Accounting Policies (Revenue Recognition) (Details)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Sales Revenue, Services, Net [Member]
Concentration Risk [Line Items]
Service revenue, as a percentage of total revenue	10.00%	10.00%	10.00%
Minimum [Member]
Concentration Risk [Line Items]
Service contract terms	12 months
Maximum [Member]
Concentration Risk [Line Items]
Service contract terms	36 months