Cash, Cash Equivalents, and Short-Term Investments (Tables)

9 Months Ended

Sep. 30, 2016

Cash And Cash Equivalents [Abstract]

Summary of Cash, Cash Equivalents and Short-Term Investments

Cash, cash equivalents and short-term investments consist of the following (in thousands):

	As of September 30, 2016
			Gross		Gross
	Amortized		Unrealized		Unrealized		Fair
	Cost		Gains		Losses		Value
Cash and cash equivalents:
Cash	$	61,609	$	—	$	—	$	61,609
Commercial paper		10,246		—		2		10,244
Money market funds		38,164		—		—		38,164
Total	$	110,019	$	—	$	2	$	110,017
Short-term investments:
Commercial paper	$	19,200	$	—	$	16	$	19,184
Corporate debt obligations		100,628		8		176		100,460
US government agencies		19,002		8		7		19,003
Bank deposits		10,367		—		—		10,367
Total	$	149,197	$	16	$	199	$	149,014

	As of December 31, 2015
			Gross		Gross
	Amortized		Unrealized		Unrealized		Fair
	Cost		Gains		Losses		Value
Cash and cash equivalents:
Cash	$	57,906	$	—	$	—	$	57,906
Bank deposits		10,253		—		—		10,253
Commercial paper		13,896		—		3		13,893
Money market funds		86,200		—		—		86,200
Total	$	168,255	$	—	$	3	$	168,252
Short-term investments:
Corporate debt obligations	$	86,590	$	2	$	300	$	86,292
Bank deposits		10,263		—		—		10,263
Total	$	96,853	$	2	$	300	$	96,555

Summary of Cost and Estimated Fair Value of Short-Term Investments

The following table summarizes the cost and estimated fair value of short-term investments based on stated effective maturities as of September 30, 2016 (in thousands):

	As of September 30, 2016
			Estimated
	Amortized		Fair
	Cost		Value
Short-term investments:
Due within one year	$	83,416	$	83,357
Due within two years		65,781		65,657
Total	$	149,197	$	149,014

Schedule of Short-Term Investments at Fair Value and Length of Continuous Unrealized Loss Position

The following tables show the short-term investments in an unrealized loss position and the related gross unrealized losses and fair value and length of time that the short-term investments have been in a continuous unrealized loss position (in thousands):

	As of September 30, 2016
	Less than 12 Months				12 Months or Greater				Total
	Fair Value		Unrealized Losses		Fair Value		Unrealized Losses		Fair Value		Unrealized Losses
Commercial paper	$	19,184	$	16	$	—	$	—	$	19,184	$	16
Corporate debt obligations		51,523		137		38,676		39		90,199	$	176
US government agencies		9,998		7		-		-		9,998		7
	$	80,705	$	160	$	38,676	$	39	$	119,381	$	199

	As of December 31, 2015
	Less than 12 Months				12 Months or Greater				Total
	Fair Value		Unrealized Losses		Fair Value		Unrealized Losses		Fair Value		Unrealized Losses
Corporate debt obligations	$	73,673	$	286	$	10,609	$	14	$	84,282	$	300
	$	73,673	$	286	$	10,609	$	14	$	84,282	$	300