Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2016

Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis

The following table sets forth the Company’s financial instruments that were measured at fair value on a recurring basis by level within the fair value hierarchy (in thousands):

	December 31, 2016
	Level 1		Level 2		Level 3		Total
Financial Assets:
Money market funds	$	54,318	$	—	$	—	$	54,318
U.S. government and agency securities		—		166,800		—		166,800
Corporate debt securities		—		77,880		—		77,880
Commercial paper		—		49,643		—		49,643
Total	$	54,318	$	294,323	$	—	$	348,641
Financial Liabilities:
Contingent consideration related to acquisition	$	—	$	—	$	4,032	$	4,032
Total	$	—	$	—	$	4,032	$	4,032

	December 31, 2015
	Level 1		Level 2		Level 3		Total
Financial Assets:
Money market funds	$	104,602	$	—	$	—	$	104,602
U.S. government and agency securities		—		194,055		—		194,055
Corporate debt securities		—		74,918		—		74,918
Commercial paper		—		42,295		—		42,295
Total	$	104,602	$	311,268	$	—	$	415,870
Financial Liabilities:
Contingent consideration related to acquisition		—		—		3,750	$	3,750
Total	$	—	$	—	$	3,750	$	3,750

Summary of Changes in Fair Value of Level 3 Financial Liabilities

The following table sets forth a summary of the changes in the fair value of the Company’s Level 3 financial liabilities (in thousands):

	Contingent Consideration			Preferred Stock Warrant Liability			Common Stock Warrant Liability
Balance at December 31, 2014	$	—		$	100		$	889
Net increase in fair value upon revaluation		—			1,108			24,969
Reclassification to additional paid-in capital		—			(1,208	)		(25,858	)
Contingent consideration recognized from acquisition		3,775			—			—
Foreign currency impact		(25	)		—			—
Balance at December 31, 2015		3,750			—			—
Net increase in fair value upon revaluation		400			—			—
Foreign currency impact		(118	)		—			—
Balance at December 31, 2016	$	4,032		$	—		$	—

Summary of Estimated Value of Cash Equivalents and Marketable Securities and Gross Unrealized Holding Gains and Losses

The following tables summarize the estimated value of the Company’s cash equivalents and marketable securities and the gross unrealized holding gains and losses (in thousands):

	December 31, 2016
	Amortized cost		Unrealized gains		Unrealized losses			Estimated Fair Value
Cash and cash equivalents:
Cash	$	13,265	$	—	$	—		$	13,265
Money market funds		54,318		—		—			54,318
Commercial paper		7,349		—		—			7,349
Total cash and cash equivalents	$	74,932	$	—	$	—		$	74,932
Marketable securities:
U.S. government and agency securities	$	166,854	$	7	$	(61	)	$	166,800
Corporate debt securities		77,967		—		(87	)		77,880
Commercial paper		42,294		—		—			42,294
Total marketable securities	$	287,115	$	7	$	(148	)	$	286,974

	December 31, 2015
	Amortized cost		Unrealized gains		Unrealized losses			Estimated Fair Value
Cash and cash equivalents:
Cash	$	15,175	$	—	$	—		$	15,175
Money market funds		104,602		—		—			104,602
Commercial paper		7,899		—		—			7,899
U.S. government and agency securities		22,780							22,780
Total cash and cash equivalents	$	150,456	$	—	$	—		$	150,456
Marketable securities:
U.S. government and agency securities	$	171,416	$	3	$	(144	)	$	171,275
Corporate debt securities		74,958		38		(78	)		74,918
Commercial paper		34,396		—		—			34,396
Total marketable securities	$	280,770	$	41	$	(222	)	$	280,589

Summary of Amortized Cost and Estimated Fair Value of Available-for-Sale Marketable Securities by Contractual Maturity

The amortized cost and estimated fair value of the Company’s available-for-sale marketable securities by contractual maturity are summarized below as of December 31, 2016 (in thousands):

	Amortized cost		Estimated Fair Value
Mature in one year or less	$	272,619	$	272,500
Mature after one year through two years		14,496		14,474
Total available-for-sale marketable securities	$	287,115	$	286,974