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

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Exercise price per share or per unit of warrants or rights outstanding.

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Number of securities into which each warrant or right may be converted. For example, but not limited to, each warrant may be converted into two shares.

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Amount, after accumulated amortization, of debt premium.

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Amount as of the balance sheet date of the unamortized adjustment to the carrying value of an interest-bearing hedged item made under an effective fair value hedge that is amortized upon discontinuation of the fair value hedge.

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Amount of increase (decrease) in the fair value of derivatives recognized in the income statement.

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Amount of expense (income) related to adjustment to fair value of warrant liability.

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Value of outstanding derivative securities that permit the holder the right to purchase securities (usually equity) from the issuer at a specified price.

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Derivative Instruments (Narrative) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2016	Dec. 31, 2017
Derivative [Line Items]
Number of securities called by each warrant or right			84.5
Exercise price of warrants or rights			$ 6.43
Warrants and rights outstanding	$ 24			$ 70
Fair Value Adjustment of Warrants	(46)	$ 62
Foreign currency forward contracts
Derivative [Line Items]
Notional amount	734			$ 767
Fair Value Hedging \| Interest rate swap
Derivative [Line Items]
Debt instrument, unamortized premium	0
Cash Flow Hedging [Member] \| Interest Rate Lock Commitments [Member]
Derivative [Line Items]
Deferred (gain) loss on discontinuation of fair value hedge	9
Other, Net \| Not Designated as Hedging Instrument \| Foreign currency forward contracts
Derivative [Line Items]
Derivative, Gain (Loss) on Derivative, Net	$ 1	$ (7)
Capital in Excess of Par Value
Derivative [Line Items]
Stock issued during period, shares, new issues			84.5