Goodwill And Other Intangible Assets (Schedule of Indefinite-Lived Intangible Assets) (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Trade Names and Trademarks [Member]
Indefinite-lived Intangible Assets [Line Items]
Indefinite-lived intangible assets	$ 17,510	$ 17,257