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, 2015	Dec. 31, 2014
Cash, cash equivalents and marketable securities [Line Items]
Less: Restricted cash, cash equivalents, and marketable securities	[1]	$ (285)	$ (450)
Cash, Cash Equivalents, and Short-term Investments		19,808	17,416
Cash
Cash, cash equivalents and marketable securities [Line Items]
Cost or Amortized Cost		6,201	4,155
Gross Unrealized Gains		0	0
Gross Unrealized Losses		0	0
Cash, Cash Equivalents, and Short-term Investments		6,201	4,155
Cash, cash equivalents, and marketable securities
Cash, cash equivalents and marketable securities [Line Items]
Cost or Amortized Cost		20,089	17,865
Gross Unrealized Gains		12	4
Gross Unrealized Losses		(8)	(3)
Cash, Cash Equivalents, and Short-term Investments		20,093	17,866
Level 1 Securities | Money market funds
Cash, cash equivalents and marketable securities [Line Items]
Cost or Amortized Cost		8,025	10,718
Gross Unrealized Gains		0	0
Gross Unrealized Losses		0	0
Cash, Cash Equivalents, and Short-term Investments		8,025	10,718
Level 1 Securities | Equity securities
Cash, cash equivalents and marketable securities [Line Items]
Cost or Amortized Cost		4	2
Gross Unrealized Gains		11	2
Gross Unrealized Losses		0	0
Cash, Cash Equivalents, and Short-term Investments		15	4
Level 2 Securities | Foreign government and agency securities
Cash, cash equivalents and marketable securities [Line Items]
Cost or Amortized Cost		49	80
Gross Unrealized Gains		0	0
Gross Unrealized Losses		0	0
Cash, Cash Equivalents, and Short-term Investments		49	80
Level 2 Securities | U.S. government and agency securities
Cash, cash equivalents and marketable securities [Line Items]
Cost or Amortized Cost		5,171	2,407
Gross Unrealized Gains		1	1
Gross Unrealized Losses		(5)	(2)
Cash, Cash Equivalents, and Short-term Investments		5,167	2,406
Level 2 Securities | Corporate debt securities
Cash, cash equivalents and marketable securities [Line Items]
Cost or Amortized Cost		479	401
Gross Unrealized Gains		0	1
Gross Unrealized Losses		(2)	(1)
Cash, Cash Equivalents, and Short-term Investments		477	401
Level 2 Securities | Asset-backed securities
Cash, cash equivalents and marketable securities [Line Items]
Cost or Amortized Cost		118	69
Gross Unrealized Gains		0	0
Gross Unrealized Losses		(1)	0
Cash, Cash Equivalents, and Short-term Investments		117	69
Level 2 Securities | Other fixed income securities
Cash, cash equivalents and marketable securities [Line Items]
Cost or Amortized Cost		42	33
Gross Unrealized Gains		0	0
Gross Unrealized Losses		0	0
Cash, Cash Equivalents, and Short-term Investments		$ 42	$ 33

[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.”