Comprehensive Income (Loss) (Schedule of Accumulated Comprehensive Income (Loss)) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at the beginning of period	$ (1,940)	$ (1,709)	$ (1,271)
Other comprehensive income (loss) before reclassifications	531	(331)	(1,001)
Reclassifications from accumulated other comprehensive loss	0	100	563
Other comprehensive income (loss), net of tax	531	(231)	(438)
Balance at the end of period	(1,409)	(1,940)	(1,709)
Foreign Currency Translation Adjustments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at the beginning of period	(1,928)	(1,545)	(920)
Other comprehensive income (loss) before reclassifications	534	(383)	(625)
Reclassifications from accumulated other comprehensive loss	0	0	0
Other comprehensive income (loss), net of tax	534	(383)	(625)
Balance at the end of period	(1,394)	(1,928)	(1,545)
Unrealized Gains (Losses) On Available-for-sale Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at the beginning of period	(12)	(17)	61
Other comprehensive income (loss) before reclassifications	(3)	(1)	(78)
Reclassifications from accumulated other comprehensive loss	0	6	0
Other comprehensive income (loss), net of tax	(3)	5	(78)
Balance at the end of period	(15)	(12)	(17)
Foreign Exchange Forward Contracts [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at the beginning of period	0	(147)	(412)
Other comprehensive income (loss) before reclassifications	0	53	(298)
Reclassifications from accumulated other comprehensive loss	0	94	563
Other comprehensive income (loss), net of tax	0	147	265
Balance at the end of period	$ 0	$ 0	$ (147)