Fair Value Measurements

3 Months Ended

Mar. 31, 2017

Fair Value Disclosures [Abstract]

Fair Value Measurements

Fair Value Measurements

Our assets and liabilities which require fair value measurement consist of cash and cash equivalents, marketable securities, accounts receivable, investments, accounts payable, and accrued liabilities. Cash equivalents, accounts receivable, accounts payable and accrued liabilities are stated at carrying amounts as reported in the condensed consolidated financial statements, which approximates fair value due to their short-term nature.

Assets and liabilities recorded at fair value on a recurring basis in the accompanying consolidated balance sheets are categorized based upon the level of judgment associated with the inputs used to measure their fair value. We use a fair value hierarchy to measure fair value, maximizing the use of observable inputs and minimizing the use of unobservable inputs. The three-tiers of the fair value hierarchy are as follows:

Level I-Inputs are unadjusted, quoted prices in active markets for identical assets or liabilities at the measurement date;

Level II-Inputs are observable, unadjusted quoted prices in active markets for similar assets or liabilities, unadjusted quoted prices for identical or similar assets or liabilities in markets that are not active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the related assets or liabilities; and

Level III-Unobservable inputs that are supported by little or no market data for the related assets or liabilities and typically reflect management’s estimate of assumptions that market participants would use in pricing the asset or liability.

We measure and report our cash equivalents and available-for-sale marketable securities at fair value. The following table sets forth the fair value of our financial assets by level within the fair value hierarchy (in thousands):

	March 31, 2017
	Level I		Level II		Level III		Total
Financial Assets:
Money market funds	$	309,438	$	—	$	—	$	309,438
Money market funds-restricted	5,497		—		—		5,497
Commercial Paper	29,883		—		—		29,883
U.S. government notes	98,377		—		—		98,377
Corporate bonds	—		168,415		—		168,415
Total financial assets	$	443,195	$	168,415	$	—	$	611,610

	December 31, 2016
	Level I		Level II		Level III		Total
Financial Assets:
Money market funds	$	305,182	$	—	$	—	$	305,182
Money market funds-restricted	4,245		—		—		4,245
Commercial Paper	5,962		—		—		5,962
U.S. government notes	110,756		—		—		110,756
Corporate bonds	—		183,192		—		183,192
Total financial assets	$	426,145	$	183,192	$	—	$	609,337