Cash, Cash Equivalents, and Marketable Securities (Tables)

6 Months Ended

Jun. 30, 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			June 30, 2017
	Total Estimated Fair Value			Cost or Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Total Estimated Fair Value
Cash	$	6,883		$	6,445	$	—	$	—		$	6,445
Level 1 securities:
Money market funds	11,940			7,201		—		—			7,201
Equity securities	51			32		32		—			64
Level 2 securities:
Foreign government and agency securities	337			487		—		—			487
U.S. government and agency securities	4,816			4,556		1		(8		)	4,549
Corporate debt securities	2,104			2,598		2		(2		)	2,598
Asset-backed securities	353			608		—		(3		)	605
Other fixed income securities	97			150		—		—			150
	$	26,581		$	22,077	$	35	$	(13	)	$	22,099
Less: Restricted cash, cash equivalents, and marketable securities (1)	(600		)								(648		)
Total cash, cash equivalents, and marketable securities	$	25,981									$	21,451

___________________

(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 June 30, 2017 (in millions):

	Amortized Cost		Estimated Fair Value
Due within one year	$	12,088	$	12,085
Due after one year through five years	3,021		3,017
Due after five years through ten years	176		175
Due after ten years	315		313
Total	$	15,600	$	15,590