Long-term Debt (Details) £ in Millions, $ in Millions, ¥ in Billions	9 Months Ended
Sep. 30, 2019 USD ($)	Sep. 30, 2019 GBP (£)	Sep. 30, 2019 JPY (¥)
Debt Instrument [Line Items]
Redemption Premium	$ 40
Debt Issuance Costs, Gross	9
Senior Debt GBP 400 Million June 2020 [Member]
Debt Instrument [Line Items]
Repayments of Debt	$ 509	£ 400
Debt Instrument, Interest Rate, Stated Percentage	5.25%		5.25%
Debt Instrument, Maturity Date	Jun. 29, 2020	Jun. 29, 2020
Senior Debt $368 Million February 2021 [Member]
Debt Instrument [Line Items]
Repayments of Debt	$ 368
Debt Instrument, Interest Rate, Stated Percentage	4.75%		4.75%
Debt Instrument, Maturity Date	Feb. 08, 2021	Feb. 08, 2021
Senior Debt Yen 25.2 Billion May 2026 [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount	$ 230		¥ 25.2
Debt Instrument, Interest Rate, Stated Percentage	0.495%		0.495%
Debt Instrument, Maturity Date	May 22, 2026	May 22, 2026
Senior Debt Yen 64.9 Billion May 2029 [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount	$ 591		¥ 64.9
Debt Instrument, Interest Rate, Stated Percentage	0.769%		0.769%
Debt Instrument, Maturity Date	May 23, 2029	May 23, 2029
Senior Debt Yen 10.7 Billion May 2031 [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount	$ 98		¥ 10.7
Debt Instrument, Interest Rate, Stated Percentage	0.898%		0.898%
Debt Instrument, Maturity Date	May 23, 2031	May 23, 2031
Senior Debt Yen 26.5 Billion May 2034 [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount	$ 241		¥ 26.5
Debt Instrument, Interest Rate, Stated Percentage	1.189%		1.189%
Debt Instrument, Maturity Date	May 23, 2034	May 23, 2034
Senior Debt Yen 24.4 Billion May 2039 [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount	$ 222		¥ 24.4
Debt Instrument, Interest Rate, Stated Percentage	1.385%		1.385%
Debt Instrument, Maturity Date	May 23, 2039	May 23, 2039

Face (par) amount of debt instrument at time of issuance.

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Contractual interest rate for funds borrowed, under the debt agreement.

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Amount, before accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

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The excess of the (1) fair value of consideration transferred to the holders of a security in excess of (2) the carrying amount of the security reported on the registrant's balance sheet, which will be deducted from net earnings to derive net earnings available to common shareholders. This amount is generally an adjustment considered in the computation of earnings per share.

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