INVESTMENTS (Tables)

12 Months Ended

Dec. 31, 2012

INVESTMENTS

Summary of amortized cost, unrealized gains and estimated fair values of available-for-sale securities

	December 31,
	2012		2011
	(in thousands)
U.S. Treasury Bonds, stripped of interest, maturing 2020 and 2022, aggregate par value of $1.6 million and $1.7 million, respectively
Amortized cost	$	943	$	894
Gross unrealized gains		472		455
Estimated fair value	$	1,415	$	1,349

Schedule of amortized cost and estimated fair values of available-for-sale securities, by contractual maturity

The amortized cost and estimated fair values of available-for-sale securities, by contractual maturity at December 31, 2012 are shown below.

	Amortized cost		Estimated fair value
	(in thousands)
Due within one year	$	94	$	142
Due after one year through five years		—		—
Due after five years through ten years		849		1,273
Due after ten years		—		—
Total	$	943	$	1,415