Income Taxes (Schedule of the Reconciliation of Unrecognized Tax Benefits) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Balance at January 1	$ 1,623	$ 1,194	$ 1,117
Changes in unrecognized tax benefits as a result of tax positions taken during a prior year	(15)	407	10
Changes in unrecognized tax benefits as a result of tax position taken during the current year	263	311	277
Decreases in unrecognized tax benefits relating to settlements with taxing authorities
Reductions to unrecognized tax benefits as a result of a lapse of the applicable statute of limitations	(239)	(289)	(210)
Balance at December 31	$ 1,632	$ 1,623	$ 1,194