Cash, Cash Equivalents And Marketable Securities (Tables)

9 Months Ended

Sep. 30, 2018

Cash, Cash Equivalents And Marketable Securities [Abstract]

Summary Of The Amortized Costs And Fair Values Of Marketable Securities

	(In Thousands)
	MARKETABLE SECURITIES
	Amortized Cost		Fair Value		Gross Unrealized Gains		Gross Unrealized Losses
September 30, 2018
Tax-exempt  Municipal Bonds	$	29,606	$	29,541	$	-	$	65
Variable Rate Demand Notes		72,975		72,975		-		-
Total Marketable Securities	$	102,581	$	102,516	$	-	$	65
December 31, 2017
Tax-exempt Municipal Bonds	$	30,103	$	29,994	$	-	$	109
Variable Rate Demand Notes		114,258		114,258		-		-
Total Marketable Securities	$	144,361	$	144,252	$	-	$	109