Cash, Cash Equivalents, and Marketable Securities - Summary by Major Security Type Cash Cash Equivalents and Marketable Securities Measured at Fair Value on Recurring Basis and Categorized Using Fair Value Hierarchy (Detail) - USD ($) $ in Millions		Dec. 31, 2016	Dec. 31, 2015
Cash, cash equivalents and marketable securities [Line Items]
Less: Restricted cash, cash equivalents, and marketable securities	[1]	$ (600)	$ (285)
Cash, Cash Equivalents, and Short-term Investments		25,981	19,808
Cash
Cash, cash equivalents and marketable securities [Line Items]
Cost or Amortized Cost		6,883	6,201
Gross Unrealized Gains		0	0
Gross Unrealized Losses		0	0
Cash, Cash Equivalents, and Short-term Investments		6,883	6,201
Cash, cash equivalents, and marketable securities
Cash, cash equivalents and marketable securities [Line Items]
Cost or Amortized Cost		26,558	20,089
Gross Unrealized Gains		34	12
Gross Unrealized Losses		(11)	(8)
Cash, Cash Equivalents, and Short-term Investments		26,581	20,093
Level 1 Securities | Money market funds
Cash, cash equivalents and marketable securities [Line Items]
Cost or Amortized Cost		11,940	8,025
Gross Unrealized Gains		0	0
Gross Unrealized Losses		0	0
Cash, Cash Equivalents, and Short-term Investments		11,940	8,025
Level 1 Securities | Equity securities
Cash, cash equivalents and marketable securities [Line Items]
Cost or Amortized Cost		20	4
Gross Unrealized Gains		31	11
Gross Unrealized Losses		0	0
Cash, Cash Equivalents, and Short-term Investments		51	15
Level 2 Securities | Foreign government and agency securities
Cash, cash equivalents and marketable securities [Line Items]
Cost or Amortized Cost		337	49
Gross Unrealized Gains		0	0
Gross Unrealized Losses		0	0
Cash, Cash Equivalents, and Short-term Investments		337	49
Level 2 Securities | U.S. government and agency securities
Cash, cash equivalents and marketable securities [Line Items]
Cost or Amortized Cost		4,821	5,171
Gross Unrealized Gains		2	1
Gross Unrealized Losses		(7)	(5)
Cash, Cash Equivalents, and Short-term Investments		4,816	5,167
Level 2 Securities | Corporate debt securities
Cash, cash equivalents and marketable securities [Line Items]
Cost or Amortized Cost		2,105	479
Gross Unrealized Gains		1	0
Gross Unrealized Losses		(2)	(2)
Cash, Cash Equivalents, and Short-term Investments		2,104	477
Level 2 Securities | Asset-backed securities
Cash, cash equivalents and marketable securities [Line Items]
Cost or Amortized Cost		355	118
Gross Unrealized Gains		0	0
Gross Unrealized Losses		(2)	(1)
Cash, Cash Equivalents, and Short-term Investments		353	117
Level 2 Securities | Other fixed income securities
Cash, cash equivalents and marketable securities [Line Items]
Cost or Amortized Cost		97	42
Gross Unrealized Gains		0	0
Gross Unrealized Losses		0	0
Cash, Cash Equivalents, and Short-term Investments		$ 97	$ 42

[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 7—Commitments and Contingencies.”