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

12 Months Ended

Dec. 31, 2015

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 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

	As of December 31, 2014
			Gross		Gross
	Amortized		Unrealized		Unrealized		Fair
	Cost		Gains		Losses		Value
Cash and cash equivalents:
Cash	$	26,284	$	—	$	—	$	26,284
Bank deposits		11,877		—		—		11,877
Commercial paper		18,341		—		2		18,339
Money market funds		11,596		—		—		11,596
Total	$	68,098	$	—	$	2	$	68,096
Short-term investments:
Corporate debt obligations	$	31,404	$	3	$	53		31,354
Bank deposits		10,270		—		—		10,270
Total	$	41,674	$	3	$	53	$	41,624

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

The following table sets forth the cost and estimated fair value of short-term investments based on stated effective maturities as of December 31, 2015 (in thousands):

	As of December 31, 2015
			Estimated
	Amortized		Fair
	Cost		Value
Short-term investments:
Due in 2016	$	53,086	$	53,003
Due in 2017		43,767		43,552
Total	$	96,853	$	96,555

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 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

	As of December 31, 2014
	Less than 12 Months				12 Months or Greater				Total
	Fair Value		Unrealized Losses		Fair Value		Unrealized Losses		Fair Value		Unrealized Losses
Corporate debt obligations	$	12,735	$	47	$	12,088	$	6	$	24,823	$	53