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

3 Months Ended

Mar. 31, 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 March 31, 2016
			Gross		Gross
	Amortized		Unrealized		Unrealized		Fair
	Cost		Gains		Losses		Value
Cash and cash equivalents:
Cash	$	51,182	$	—	$	—	$	51,182
Bank deposits		10,262		—		—		10,262
Commercial paper		20,921		—		2		20,919
Money market funds		76,328		—		—		76,328
Total	$	158,693	$	—	$	2	$	158,691
Short-term investments:
Commercial paper	$	11,548	$	—	$	—	$	11,548
Corporate debt obligations		63,665		16		64		63,617
US government agencies		14,514		12		3		14,523
Bank deposits		10,366		—		—		10,366
Total	$	100,093	$	28	$	67	$	100,054

	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 March 31, 2016 (in thousands):

	As of March 31, 2016
			Estimated
	Amortized		Fair
	Cost		Value
Short-term investments:
Due within one year	$	66,464	$	66,422
Due within two years		33,629		33,632
Total	$	100,093	$	100,054

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 March 31, 2016
	Less than 12 Months				12 Months or Greater				Total
	Fair Value		Unrealized Losses		Fair Value		Unrealized Losses		Fair Value		Unrealized Losses
Commercial paper	$	11,548	$	—	$	—	$	—	$	11,548	$	—
Corporate debt obligations		33,916		55		13,116		9		47,032	$	64
US government agencies		3,999		3						3,999		3
	$	49,463	$	58	$	13,116	$	9	$	62,579	$	67

	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