Investments (Tables)

12 Months Ended

Dec. 31, 2013

Investments, Held-to-Maturity Securities

The amortized cost and fair value of our investments that are being accounted for as held-to-maturity securities, and the related gross unrealized gains and losses, were as follows as of the dates shown below (in thousands):

			Gross Unrealized
	Cost		Gains		Losses		Fair value
As of December 31, 2013:
Short-term Investments:
Corporate bonds	$	18,351	$	234	$	—	$	18,585
Long-term Investments:
Corporate bonds	$	10,069	$	285	$	—	$	10,354
As of December 31, 2012:
Short-term Investments:
Corporate bonds	$	8,182	$	78	$	—	$	8,260
Long-term Investments:
Corporate bonds	$	28,433	$	652	$	29	$	29,056