Segment Reporting (Schedule Of Operating Information, Segment) (Parenthetical) (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Segment Reporting [Abstract]
Net revenues accounted for by individual client, maximum percentage	10.00%	10.00%	10.00%	10.00%