Marketable Securities (Narrative) (Details) - USD ($) shares in Thousands, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2015	Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Gross Unrealized Loss	$ 15	$ 73
Available-For-Sale Securities Number of Securities Owned	51
Available-For-Sale Securities Number Of Securities Owned Unrealized Losses	27
Available-for-sale Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Gross Unrealized Loss	$ 100