Fair Values Of Assets And Liabilities (Tables)

3 Months Ended

Mar. 31, 2013

Fair Values Of Assets And Liabilities [Abstract]

Schedule Of Assets Measured At Fair Value On A Recurring Basis

		Total		Level 1		Level 2		Level 3
March 31, 2013
Repurchase agreement	$	100	$	0	$	100	$	0
Marketable securities	$	10,254,243	$	10,254,243	$	0	$	0
December 31, 2012
Repurchase agreement	$	100	$	0	$	100	$	0
Money market	$	2,829,397	$	2,829,397	$	0	$	0
Marketable securities	$	10,158,016	$	10,158,016	$	0	$	0

Schedule Of Estimated Fair Value Of Long-Term Obligation Included In Financial Statements

The estimated fair values (in thousands) of the long-term obligations included in the financial statements at March 31, 2013, are as follows:
	Carrying Value		Fair Value
Long-term obligations (including current installments)	$	522,681	$	543,646