Segment And Geographic Information (Schedule Of Net Revenues By Geographic Location) (Details) - USD ($) $ in Thousands	3 Months Ended												12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenues	$ 39,838	$ 36,703	$ 35,526	$ 33,831	$ 37,151	$ 37,069	$ 34,690	$ 35,731	$ 35,457	$ 36,250	$ 33,520	$ 35,536	$ 145,898	$ 144,641	$ 140,763
U.S. [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenues													114,978	110,533	109,325
International [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenues													$ 30,920	$ 34,108	$ 31,438