Short-term Investments (Tables)

12 Months Ended

Dec. 31, 2013

Short-term Investments [Abstract]

Short-term Investments

Short-term marketable securities for the periods presented were comprised of the following (in thousands):

	December 31, 2013
Security Type	Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
U.S. government fixed income securities	$	130,971	$	21	$	(975	)	$	130,017
Total short-term investments	$	130,971	$	21	$	(975	)	$	130,017

	December 31, 2012
Security Type	Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
U.S. government fixed income securities	$	87,394	$	20	$	(411	)	$	87,003
Equity securities of certain technology companies	3,254		—		(782		)	2,472
Total short-term investments	$	90,648	$	20	$	(1,193	)	$	89,475