Investments

3 Months Ended

Mar. 31, 2015

Investments, Debt and Equity Securities [Abstract]

Investments

Note 5. Investments

We have cash investment policies that limit investments to investment grade rated securities. At March 31, 2015 and December 31, 2014, all of our investments were classified as available-for-sale and carried at fair value. At March 31, 2015 and December 31, 2014, our short-term and long-term investments had maturity dates of less than twenty-four months.

The amortized cost and fair value of our investments, with gross unrealized gains and losses, were as follows:

	Amortized Cost Basis		Gross Unrealized Gains		Gross Unrealized Losses			Aggregate Fair Value
	(in thousands)
At March 31, 2015
Short-term investments:
Corporate debt	$	45,940	$	1	$	(136	)	$	45,805
U.S. government agency debt		15,000		1		(7	)		14,994
Certificates of deposit		9,555		—		—			9,555
Total short-term investments	$	70,495	$	2	$	(143	)	$	70,354
Long-term investments:
Certificates of deposit	$	1,225	$	—	$	—		$	1,225
Total long-term investments	$	1,225	$	—	$	—		$	1,225

	Amortized Cost Basis		Gross Unrealized Gains		Gross Unrealized Losses			Aggregate Fair Value
	(in thousands)
At December 31, 2014
Short-term investments:
Corporate debt	$	51,241	$	8	$	(244	)	$	51,005
U.S. government agency debt		15,000		—		(25	)		14,975
Certificates of deposit		9,555		—		—			9,555
Total short-term investments	$	75,796	$	8	$	(269	)	$	75,535
Long-term investments:
Certificates of deposit	$	1,225	$	—	$	—		$	1,225
Total long-term investments	$	1,225	$	—	$	—		$	1,225

For the three months ended March 31, 2015 and 2014, we did not have any realized gains or losses on our investments. At March 31, 2015 and December 31, 2014, none of our available-for-sale investments had been in a continuous loss position for more than twelve months. As of March 31, 2015, a total of 16 individual securities had been in an unrealized loss position for twelve months or less and the losses were determined to be temporary. We regularly review our investment portfolio to determine if any security is other-than-temporarily impaired, which would require us to record an impairment charge in the period any such determination is made. In making this judgment, we evaluate, among other things, the duration and extent to which the fair value of a security has been less than its amortized cost, the financial condition of the issuer, the time to maturity of the investment and our intent to sell the security prior to maturity where we would not be able to recover its amortized cost basis.