Marketable Securities (Narrative) (Details) $ in Millions	3 Months Ended
	Mar. 31, 2016 USD ($) shares
Schedule of Available-for-sale Securities [Line Items]
Available-For-Sale Securities Number of Securities Owned	69
Available-For-Sale Securities Number Of Securities Owned Unrealized Losses	9
Available-for-sale Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Gross Unrealized Loss | $	$ 0.1