4. Cash, Cash Equivalents and Short-Term Investments

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

	As of December 31, 2016
			Gross		Gross
	Amortized		Unrealized		Unrealized		Fair
	Cost		Gains		Losses		Value
Cash and cash equivalents:
Cash	$	63,642	$	—	$	—	$	63,642
Commercial paper		6,995		—		2		6,993
Money market funds		36,708		—		—		36,708
Total	$	107,345	$	—	$	2	$	107,343
Short-term investments:
Commercial paper	$	14,245	$	—	$	8	$	14,237
Corporate debt obligations		110,062		—		347		109,715
US government agencies		18,998		2		50		18,950
Bank deposits		10,846		1		—		10,847
Total	$	154,151	$	3	$	405	$	153,749

	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 sets forth the cost and estimated fair value of short-term investments based on stated effective maturities as of December 31, 2016 (in thousands):

	As of December 31, 2016
			Estimated
	Amortized		Fair
	Cost		Value
Short-term investments:
Due in 2017	$	84,406	$	84,315
Due in 2018		69,745		69,434
Total	$	154,151	$	153,749

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 years ended December 31, 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 December 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	$	14,237	$	8					$	14,237	$	8
Corporate debt obligations		78,821		323		29,689		24		108,510		347
US government agencies		11,451		46		3,496		4		14,947		50

	$	104,509	$	377	$	33,185	$	28	$	137,694	$	405

	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