Cash, Cash Equivalents And Marketable Securities (Tables)

3 Months Ended

Mar. 31, 2019

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
March 31, 2019
Tax-exempt  Municipal Bonds	$	47,700	$	47,814	$	120	$	6
Variable Rate Demand Notes		49,953		49,953		-		-
Total Marketable Securities	$	97,653	$	97,767	$	120	$	6
December 31, 2018
Tax-exempt Municipal Bonds	$	40,156	$	40,182	$	44	$	18
Variable Rate Demand Notes		94,416		94,416		-		-
Total Marketable Securities	$	134,572	$	134,598	$	44	$	18