Fair Value of Financial Instruments (Tables)

9 Months Ended

Sep. 30, 2016

Fair Value Disclosures [Abstract]

Schedule of Cash and Cash Equivalents, Available-for-sale Securities Reconciliation

The Company's cash and cash equivalents, short-term investments, and long-term investments consist of the following:

	September 30, 2016
	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
	(in thousands)
Cash and cash equivalents:
Cash	$	58,277	$	—	$	—		$	58,277
Money market funds	19,713		—		—			19,713
Commercial paper	20,308		1		—			20,309
Total	98,298		1		—			98,299
Short-term investments:
Commercial paper	6,863		1		—			6,864
Corporate bonds	11,173		6		(9		)	11,170
Asset-backed securities	256		—		—			256
U.S. government agencies	93,372		26		(10		)	93,388
Total	111,664		33		(19		)	111,678
Long-term investments:
Asset-backed securities	5,696		9		—			5,705
U.S. government agencies	43,776		25		(26		)	43,775
Corporate bonds	15,457		6		(13		)	15,450
Total	64,929		40		(39		)	64,930
Total	$	274,891	$	74	$	(58	)	$	274,907

	December 31, 2015
	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
	(in thousands)
Cash and cash equivalents:
Cash	$	61,372	$	—	$	—		$	61,372
Money market funds	3,980		—		—			3,980
U.S. government agencies	8,999		1		—			9,000
Commercial paper	17,345		1		—			17,346
Total	91,696		2		—			91,698
Short-term investments:
Commercial paper	10,447		1		—			10,448
Corporate bonds	12,448		—		(13		)	12,435
U.S. government agencies	64,422		3		(40		)	64,385
Total	87,317		4		(53		)	87,268
Long-term investments:
Asset-backed securities	7,007		—		(18		)	6,989
U.S. government agencies	32,683		—		(142		)	32,541
Corporate bonds	3,751		—		(4		)	3,747
Total	43,441		—		(164		)	43,277
Total	$	222,454	$	6	$	(217	)	$	222,243

Schedule of changes to accumulated other comprehensive income

The following table shows the changes to accumulated other comprehensive income for the nine months ended September 30, 2016:

	Unrealized Gain (Loss) on Investments
Balance at December 31, 2015	$	(211	)
Change in net realized gain (loss) on investments	140
Amounts reclassified for net realized gain (loss) included in net income	87
Other comprehensive income	227
Balance at September 30, 2016	$	16

Schedule of Assets Measured on Recurring Basis

The following table sets forth by level within the fair value hierarchy the fair value of the Company's available-for-sale securities measured on a recurring basis, excluding cash and money market funds:

	September 30, 2016
	Level 1		Level 2		Level 3		Fair Value
	(in thousands)
Commercial paper	$	—	$	27,173	$	—	$	27,173
U.S. government agencies	—		137,163		—		137,163
Corporate bonds	—		26,620		—		26,620
Asset-backed securities	—		5,961		—		5,961
Total	$	—	$	196,917	$	—	$	196,917

	December 31, 2015
	Level 1		Level 2		Level 3		Fair Value
	(in thousands)
Commercial paper	$	—	$	27,794	$	—	$	27,794
U.S. government agencies	—		105,926		—		105,926
Corporate bonds	—		16,182		—		16,182
Asset-backed securities	—		6,989		—		6,989
Total	$	—	$	156,891	$	—	$	156,891

Schedule of Available-for-Sale Securities by Contractual Maturity

The following summarizes the fair value of securities classified as available-for-sale by contractual, or effective, maturity:

	September 30, 2016
	Mature within One Year		After One Year through Two Years		Over Two Years		Fair Value
	(in thousands)
Commercial paper	$	27,173	$	—	$	—	$	27,173
U.S. government agencies	97,192		39,971		—		137,163
Corporate bonds	12,833		13,787		—		26,620
Asset-backed securities	5,961		—		—		5,961
Total	$	143,159	$	53,758	$	—	$	196,917

Summary of Gains (Losses) Recognized From Forward Contracts and Other Foreign Currency Transactions

The following summarizes the gains (losses) recognized from forward contracts and other foreign currency transactions:

	Three Months Ended						Nine Months Ended
	September 30,						September 30,
	2016			2015			2016			2015
	(in thousands)
Net gain (loss) from forward contracts	$	(82	)	$	109		$	(9	)	$	498
Other foreign currency transactions losses	(2		)	(377		)	(276		)	(890		)
Total foreign exchange loss, net	$	(84	)	$	(268	)	$	(285	)	$	(392	)