Cash, Cash Equivalents, and Marketable Securities (Tables)

3 Months Ended

Mar. 31, 2017

Investments, Debt and Equity Securities [Abstract]

Fair Value by Major Security Type

The following table summarizes, by major security type, our cash, cash equivalents, and marketable securities that are measured at fair value on a recurring basis and are categorized using the fair value hierarchy (in millions):

	December 31, 2016			March 31, 2017
	Total Estimated Fair Value			Cost or Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Total Estimated Fair Value
Cash	$	6,883		$	6,374	$	—	$	—		$	6,374
Level 1 securities:
Money market funds	11,940			9,643		—		—			9,643
Equity securities	51			20		31		—			51
Level 2 securities:
Foreign government and agency securities	337			282		—		—			282
U.S. government and agency securities	4,816			3,705		1		(6		)	3,700
Corporate debt securities	2,104			1,889		1		(2		)	1,888
Asset-backed securities	353			370		1		(2		)	369
Other fixed income securities	97			85		—		—			85
	$	26,581		$	22,368	$	34	$	(10	)	$	22,392
Less: Restricted cash, cash equivalents, and marketable securities (1)	(600		)								(861		)
Total cash, cash equivalents, and marketable securities	$	25,981									$	21,531

___________________

(1) We are required to pledge or otherwise restrict a portion of our cash, cash equivalents, and marketable securities as collateral for standby and trade letters of credit, guarantees, debt, real estate leases, and amounts due to third-party sellers in certain jurisdictions. We classify cash, cash equivalents, and marketable securities with use restrictions of less than twelve months as “Accounts receivable, net and other” and of twelve months or longer as non-current “Other assets” on our consolidated balance sheets. See “Note 3 — Commitments and Contingencies.”

Investments Classified by Contractual Maturity Date

The following table summarizes the contractual maturities of our cash equivalents and marketable fixed-income securities as of March 31, 2017 (in millions):

	Amortized Cost		Estimated Fair Value
Due within one year	$	13,191	$	13,190
Due after one year through five years	2,411		2,407
Due after five years through ten years	197		196
Due after ten years	175		174
Total	$	15,974	$	15,967