Summary Of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2013

Summary Of Significant Accounting Policies [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
December 31, 2013
Tax-exempt Municipal Bonds	$	20,813	$	20,825	$	18	$	6
Variable Rate Demand Notes		15,579		15,579		-		-
Total Marketable Securities	$	36,392	$	36,404	$	18	$	6
December 31, 2012
Tax-exempt Municipal Bonds	$	24,412	$	24,494	$	94	$	12
Variable Rate Demand Notes		31,092		31,092		-		-
Total Marketable Securities	$	55,504	$	55,586	$	94	$	12

Schedule Of Estimated Future Amortization Expense

Years ending December 31:	(In thousands)
2014	$	7,989
2015		7,989
2016		7,986
2017		550
2018		65

Schedule Of Changes In Product Warranty

	(In thousands)
	Year Ended December 31
	2013		2012
Beginning balance January 1	$	388	$	341
Accruals during the period		840		528
Charges / payments made under the warranties		(660)		(481)
Balance December 31	$	568	$	388