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, unless otherwise specified	Jun. 30, 2014		Dec. 31, 2013
Cash, cash equivalents and marketable securities [Line Items]
Less: Restricted cash, cash equivalents, and marketable securities	$ (389)	[1]	$ (301)	[1]
Cash, Cash Equivalents, and Short-term Investments Total Estimated Fair Value	7,986		12,447
Cash
Cash, cash equivalents and marketable securities [Line Items]
Cost or Amortized Cost	2,962
Gross Unrealized Gains	0
Gross Unrealized Losses	0
Cash, Cash Equivalents, and Short-term Investments Total Estimated Fair Value	2,962		3,008
Cash, cash equivalents, and marketable securities
Cash, cash equivalents and marketable securities [Line Items]
Cost or Amortized Cost	8,368
Gross Unrealized Gains	9
Gross Unrealized Losses	(2)
Cash, Cash Equivalents, and Short-term Investments Total Estimated Fair Value	8,375		12,748
Level 1 Securities | Money market funds
Cash, cash equivalents and marketable securities [Line Items]
Cost or Amortized Cost	2,462
Gross Unrealized Gains	0
Gross Unrealized Losses	0
Cash, Cash Equivalents, and Short-term Investments Total Estimated Fair Value	2,462		5,914
Level 1 Securities | Equity securities
Cash, cash equivalents and marketable securities [Line Items]
Cost or Amortized Cost	2
Gross Unrealized Gains	1
Gross Unrealized Losses	0
Cash, Cash Equivalents, and Short-term Investments Total Estimated Fair Value	3		4
Level 2 Securities | Foreign government and agency securities
Cash, cash equivalents and marketable securities [Line Items]
Cost or Amortized Cost	358
Gross Unrealized Gains	2
Gross Unrealized Losses	0
Cash, Cash Equivalents, and Short-term Investments Total Estimated Fair Value	360		758
Level 2 Securities | U.S. government and agency securities
Cash, cash equivalents and marketable securities [Line Items]
Cost or Amortized Cost	1,799
Gross Unrealized Gains	2
Gross Unrealized Losses	(2)
Cash, Cash Equivalents, and Short-term Investments Total Estimated Fair Value	1,799		2,222
Level 2 Securities | Corporate debt securities
Cash, cash equivalents and marketable securities [Line Items]
Cost or Amortized Cost	681
Gross Unrealized Gains	4
Gross Unrealized Losses	0
Cash, Cash Equivalents, and Short-term Investments Total Estimated Fair Value	685		741
Level 2 Securities | Asset-backed securities
Cash, cash equivalents and marketable securities [Line Items]
Cost or Amortized Cost	68
Gross Unrealized Gains	0
Gross Unrealized Losses	0
Cash, Cash Equivalents, and Short-term Investments Total Estimated Fair Value	68		65
Level 2 Securities | Other fixed income securities
Cash, cash equivalents and marketable securities [Line Items]
Cost or Amortized Cost	36
Gross Unrealized Gains	0
Gross Unrealized Losses	0
Cash, Cash Equivalents, and Short-term Investments Total Estimated Fair Value	$ 36		$ 36

[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 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.”