Fair Value Measurements (Tables)

6 Months Ended

Jun. 30, 2013

Fair Value Disclosures [Abstract]

Schedule of Short-Term Investments

Short-term Investments

	June 30, 2013
	Amortized Cost		Gross Unrealized Holding Gains		Gross Unrealized Holding Losses		Fair Value
	(In thousands)
U.S. Treasury securities	$	56,978	$	4	$	0	$	56,982
Total	$	56,978	$	4	$	0	$	56,982

	December 31, 2012
	Amortized Cost		Gross Unrealized Holding Gains		Gross Unrealized Holding Losses		Fair Value
	(In thousands)
U.S. Treasury securities	$	38,980	$	8	$	0	$	38,988
Total	$	38,980	$	8	$	0	$	38,988

Schedule of Financial Instruments Measured at Fair Value on Recurring Basis

	June 30, 2013 Fair value measurements using
	Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
	(In thousands)
Assets:
U.S. Treasury securities	$	0	$	56,982	$	0	$	56,982
Money market accounts		3,061		0		0		3,061
Total assets at fair value	$	3,061	$	56,982	$	0	$	60,043

The above table excludes $3.8 million of cash held in banks.

	December 31, 2012 Fair value measurements using
	Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
	(In thousands)
Assets:
U.S. Treasury securities	$	0	$	38,988	$	0	$	38,988
Money market accounts		52		0		0		52
Total assets at fair value	$	52	$	38,988	$	0	$	39,040