Short-term Investments

12 Months Ended

Dec. 31, 2014

Short-term Investments [Abstract]

Short-Term Investments

SHORT-TERM INVESTMENTS

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

	December 31, 2014
Security Type	Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
U.S. government fixed income securities	$	58,819	$	2	$	(263	)	$	58,558
Total short-term investments	$	58,819	$	2	$	(263	)	$	58,558

	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

Short-term investments at December 31, 2014 and 2013 were comprised of investments in highly liquid, AAA, U.S. government fixed income securities with maturity dates in 2015, and ranging from 2014 to 2015, respectively. Short-term marketable securities in unrealized loss positions at December 31, 2014 and 2013 have been in continuous unrealized loss positions for less than one year.

U.S. government fixed income securities. The gross unrealized loss can be primarily attributed to a combination of market conditions as well as the demand for and duration of the U.S. government fixed income securities. The Company has the ability to hold these securities until maturity, currently has no intent to sell, there is no requirement to sell and the Company believes that it can recover the amortized cost of these investments. The Company has found no evidence of impairment due to credit losses in its portfolio. Therefore, these unrealized losses were recorded in other comprehensive income (loss). However, the Company cannot provide any assurance that its portfolio of short-term marketable securities will not be impacted by adverse conditions in the financial markets, which may require the Company in the future to record an impairment charge for credit losses which could adversely impact its financial results.

For the year ended December 31, 2014, proceeds from the sale of short-term marketable securities classified as available-for-sale were $182,115,000 and gross realized losses were $2,188,000. Gross realized losses are recorded in the statements of operations in interest and other investment income (loss). For the year ended December 31, 2013, proceeds from the sale of short-term marketable securities classified as available-for-sale were $239,370,000, gross realized gains were $1,174,000 and gross realized losses were $981,000. For the year ended December 31, 2012, proceeds from the sale of short-term marketable securities classified as available-for-sale were $319,811,000, gross realized gains were $31,000 and gross realized losses were $555,000.