Income Taxes (Summary Of A Reconciliation Of The Beginning And Ending Amount Of Gross Unrecognized Tax Benefits ("UTB")) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Gross UTB balance at beginning of year	$ 1,757	$ 1,887	$ 1,508
Additions based on tax positions related to the current year	139	178	186
Additions for tax positions of prior years	603	0	289
Reductions for tax positions of prior years	(38)	(96)	(78)
Reductions due to lapse of applicable statute of limitations	0	(212)	(18)
Gross UTB balance at end of year	2,461	1,757	1,887
Net UTB balance at end of year	$ 159	$ 131	$ 126