Cash, Cash Equivalents, and Marketable Securities Summary by Major Security Type Cash Cash Equivalents and Marketable Securities Measured at Fair Value on Recurring (Details) - USD ($) $ in Millions		Mar. 31, 2017	Dec. 31, 2016
Cash, cash equivalents and marketable securities [Line Items]
Cash, Cash Equivalents, and Short-term Investments		$ 21,531	$ 25,981
Less: Restricted Cash and Cash Equivalents	[1]	(861)	(600)
Cash
Cash, cash equivalents and marketable securities [Line Items]
Cost or Amortized Cost		6,374
Gross Unrealized Gains		0
Gross Unrealized Losses		0
Cash, Cash Equivalents, and Short-term Investments		6,374	6,883
Cash, cash equivalents, and marketable securities
Cash, cash equivalents and marketable securities [Line Items]
Cost or Amortized Cost		22,368
Gross Unrealized Gains		34
Gross Unrealized Losses		(10)
Cash, Cash Equivalents, and Short-term Investments		22,392	26,581
Level 1 Securities | Money market funds
Cash, cash equivalents and marketable securities [Line Items]
Cost or Amortized Cost		9,643
Gross Unrealized Gains		0
Gross Unrealized Losses		0
Cash, Cash Equivalents, and Short-term Investments		9,643	11,940
Level 1 Securities | Equity securities
Cash, cash equivalents and marketable securities [Line Items]
Cost or Amortized Cost		20
Gross Unrealized Gains		31
Gross Unrealized Losses		0
Cash, Cash Equivalents, and Short-term Investments		51	51
Level 2 Securities | Foreign government and agency securities
Cash, cash equivalents and marketable securities [Line Items]
Cost or Amortized Cost		282
Gross Unrealized Gains		0
Gross Unrealized Losses		0
Cash, Cash Equivalents, and Short-term Investments		282	337
Level 2 Securities | U.S. government and agency securities
Cash, cash equivalents and marketable securities [Line Items]
Cost or Amortized Cost		3,705
Gross Unrealized Gains		1
Gross Unrealized Losses		(6)
Cash, Cash Equivalents, and Short-term Investments		3,700	4,816
Level 2 Securities | Corporate debt securities
Cash, cash equivalents and marketable securities [Line Items]
Cost or Amortized Cost		1,889
Gross Unrealized Gains		1
Gross Unrealized Losses		(2)
Cash, Cash Equivalents, and Short-term Investments		1,888	2,104
Level 2 Securities | Asset-backed securities
Cash, cash equivalents and marketable securities [Line Items]
Cost or Amortized Cost		370
Gross Unrealized Gains		1
Gross Unrealized Losses		(2)
Cash, Cash Equivalents, and Short-term Investments		369	353
Level 2 Securities | Other fixed income securities
Cash, cash equivalents and marketable securities [Line Items]
Cost or Amortized Cost		85
Gross Unrealized Gains		0
Gross Unrealized Losses		0
Cash, Cash Equivalents, and Short-term Investments		$ 85	$ 97

[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.”