Short-Term Investments

9 Months Ended

Sep. 30, 2016

Investments, Debt and Equity Securities [Abstract]

Short-Term Investments

Short-Term Investments

Debt securities that are not classified as cash equivalents are classified as available-for-sale investments and are stated at fair value.  Realized gains and losses on sales of investments are reflected in nonoperating income (expense) in the unaudited consolidated statements of operations.  Unrealized gains and losses on available-for-sale securities are reflected as a component of accumulated other comprehensive loss.

The following is a summary of short-term investments held as of September 30, 2016 and December 31, 2015:

	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
September 30, 2016	(in thousands)
Corporate debt	$	173,122	$	247	$	(93	)	$	173,276
U.S. government and agency debt	63,996		76		(18		)	64,054
Municipal bonds	21,198		—		(66		)	21,132
Other fixed income securities	29,534		1		(2		)	29,533
Total short-term investments	$	287,850	$	324	$	(179	)	$	287,995

	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
December 31, 2015	(in thousands)
Corporate debt	$	167,066	$	13	$	(481	)	$	166,598
U.S. government and agency debt	62,376		9		(123		)	62,262
Municipal bonds	22,865		3		(12		)	22,856
Other fixed income securities	26,835		—		(6		)	26,829
Total short-term investments	$	279,142	$	25	$	(622	)	$	278,545

Contractual maturities of short-term investments as of September 30, 2016 are shown below. 

	Under 1 Year		1 to 5 Years		Total
	(in thousands)
Corporate debt	$	58,812	$	114,464	$	173,276
U.S. government and agency debt	35,815		28,240		64,055
Municipal bonds	8,859		12,273		21,132
Other fixed income securities	28,032		1,500		29,532
Total short-term investments	$	131,518	$	156,477	$	287,995

The Company classifies investments as current assets as these securities are available for use in its current operations.