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)
-Number 210
-Article 12
-Section 13
-Sentence Column B

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Fair value of the assets less the liabilities of a derivative or group of derivatives.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 45
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Reference 2: http://www.xbrl.org/2003/role/presentationRef
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-Publisher FASB
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Amount of increase (decrease) in the fair value of derivatives recognized in the income statement.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
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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.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
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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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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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The aggregate fair value amounts of derivative instruments that contain credit-risk-related contingent features that are in a net liability position at the end of the reporting period. For nonderivative instruments that are designated and qualify as hedging instruments, the fair value amounts are the carrying value of the nonderivative hedging instrument, including the adjustment for the foreign currency transaction gain (loss) on that instrument.

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- Definition

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

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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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The net gain (loss) recognized in earnings during the reporting period representing the amount of the cash flow hedges' ineffectiveness.

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Derivative Financial Instruments (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Derivative [Line Items]
Gains (losses) reclassified from other comprehensive income into shareholders' net income
Amounts excluded from assessment of hedge effectiveness
Gains (losses) recognized due to hedge ineffectiveness
Fair Value
Net liability position of derivatives that contain certain credit risk-related contingent features
Gain (Loss) Recognized in Other Comprehensive Income
Gain (Loss) Recognized in Income Statement
Designated as Hedging Instrument [Member] \| Net Investment Hedge [Member] \| Foreign Currency Swaps [Member]
Derivative [Line Items]
Notional Amount	439		439		0
Designated as Hedging Instrument [Member] \| Cash Flow Hedging [Member] \| Interest Rate Swaps [Member]
Derivative [Line Items]
Notional Amount					750
Designated as Hedging Instrument [Member] \| Fair Value Hedging [Member] \| Foreign Currency Swaps [Member]
Derivative [Line Items]
Notional Amount	478		$ 478		318
Derivative contract term			30 years
Non designated [Member] \| Swaption [Member]
Derivative [Line Items]
Notional Amount
Non designated [Member] \| Forward Contracts [Member]
Derivative [Line Items]
Notional Amount	509		509		$ 255
Non designated [Member] \| Cash Flow Hedging [Member] \| Swaption [Member]
Derivative [Line Items]
Notional Amount