2. Cash, Cash Equivalents, and Short-Term Investments

The Company considers all highly liquid investments with a maturity of three months or less when purchased to be cash equivalents. Cash and cash equivalents consist of cash on hand, highly liquid investments in commercial paper, money market funds and various deposit accounts.

The Company considers all high quality investments purchased with original maturities at the date of purchase greater than three months to be short-term investments. Investments are available to be used for current operations and are, therefore, classified as current assets even though maturities may extend beyond one year. Cash equivalents and short-term investments are classified as available-for-sale and are, therefore, recorded at fair value on the condensed consolidated balance sheets, with any unrealized gains and losses reported in accumulated other comprehensive income (loss), which is reflected as a separate component of stockholders’ equity in its condensed consolidated balance sheets, until realized. The Company uses the specific-identification method to compute gains and losses on the investments. The amortized cost of securities is adjusted for amortization of premiums and accretion of discounts to maturity. Such amortization and accretion is included as a component of other income (expense), net in the condensed consolidated statements of operations.

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

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

The gross unrealized loss related to these securities was due primarily to changes in interest rates. The Company reviews its short-term investments on a regular basis to evaluate whether or not any security has experienced an other-than-temporary decline in fair value. The Company considers factors such as the length of time and extent to which the market value has been less than the cost, the financial condition and near-term prospects of the issuer and its intent to sell, or whether it is more likely than not the Company will be required to sell, the investment before recovery of the investment’s amortized cost basis. If the Company believes that an other-than-temporary decline exists in one of these securities, the Company writes down these investments to fair value. For debt securities, the portion of the write-down related to credit loss would be recorded to other income (expense), net, in the Company’s condensed consolidated statements of operations. Any portion not related to credit loss would be recorded to accumulated other comprehensive income (loss), which is reflected as a separate component of stockholders’ equity in the Company’s condensed consolidated balance sheets. During the nine months ended September 30, 2016 and 2015, the Company did not consider any of its investments to be other-than-temporarily impaired.

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