Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
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-Article 12
-Section 13
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The estimated net amount of existing gains or losses on cash flow hedges at the reporting date expected to be reclassified to earnings within the next 12 months.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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Amount of obligation to return cash collateral under master netting arrangements that have not been offset against derivative assets.

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Amount of right to receive cash collateral under master netting arrangements that have not been offset against derivative liabilities.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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No definition available.

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The effective portion of net gain (loss) reclassified from accumulated other comprehensive income into income on derivative instruments designated and qualifying as hedging instruments.

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The portion of gains and losses (net) on derivative instruments designated and qualifying as hedging instruments representing (a) the amount of the hedge ineffectiveness and (b) the amount, if any, excluded from the assessment of hedge effectiveness.

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The effective portion of gains and losses (net) on derivative instruments designated and qualifying as hedging instruments that was recognized in other comprehensive income during the current period.

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Period remaining until the derivative contract matures, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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No definition available.

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The net gain (loss) relating to components of the gain (loss) on the cash flow hedging instrument excluded from the assessment of cash flow hedge effectiveness. Recognized in earnings.

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Financial Instruments - Additional Information (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) related to interest rate swaps	$ (5,000,000)	$ 0	$ 9,000,000	$ 0
Cash Flow Hedges
Derivative Instruments, Gain (Loss) [Line Items]
Gains/(losses), net of taxes recognized in earnings/(losses)	21,000,000	16,000,000	(11,000,000)	27,000,000
Gains/(losses), net of taxes, reclassified from accumulated other comprehensive income into earnings	(5,000,000)	4,000,000	9,000,000	(3,000,000)
Interest rate contracts
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, aggregate notional value	9,117,000,000		9,117,000,000		$ 6,532,000,000
Interest rate contracts \| Cash Flow Hedges
Derivative Instruments, Gain (Loss) [Line Items]
Expected transfers of unrealized gains (losses) to earnings, within next 12 months or less			1,000,000
Gains/(losses), net of taxes recognized in earnings/(losses)	21,000,000	24,000,000	(11,000,000)	47,000,000
Gains/(losses), net of taxes, reclassified from accumulated other comprehensive income into earnings	(5,000,000)	$ 0	$ 9,000,000	$ 0
Cash Flow Hedges
Derivative Instruments, Gain (Loss) [Line Items]
Hedged forecasted transaction period			5 years 4 months 24 days
Net investment hedge contracts
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, aggregate notional value	7,114,000,000		$ 7,114,000,000		0
Gains/(losses), net of taxes recognized in earnings/(losses)	276,000,000		265,000,000
Gains/(losses), net of taxes, reclassified from accumulated other comprehensive income into earnings	0		0
Net investment hedge contracts \| Net investment hedge debt
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses), net of taxes, recognized in income, excluded from effectiveness testing	(33,000,000)		(50,000,000)
Quoted Prices in Active Markets for Identical Assets (Level 1) \| Exchange Traded Options \| Accounts payable
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, margin requirement liability	$ 25,000,000		$ 25,000,000
Quoted Prices in Active Markets for Identical Assets (Level 1) \| Exchange Traded Options \| Other current assets
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, margin deposit asset					$ 171,000,000