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

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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Debt - Summary (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019	Nov. 26, 2019	May 17, 2018	Sep. 22, 2016	May 26, 2015
Debt Instrument [Line Items]
Long-term debt	$ 3,949	$ 3,948
Senior Notes \| 4.0% Senior Notes due 2025
Debt Instrument [Line Items]
Long-term debt	$ 694	694
Stated interest rate (as a percent)	4.00%					4.00%
Unamortized debt discount and issuance costs	$ 6
Senior Notes \| 4.4% Senior Notes, due 2026
Debt Instrument [Line Items]
Long-term debt	$ 894	893
Stated interest rate (as a percent)	4.40%
Unamortized debt discount and issuance costs	$ 6
Senior Notes \| 2.95% Senior Notes due 2027
Debt Instrument [Line Items]
Long-term debt	$ 493	493
Stated interest rate (as a percent)	2.95%				2.95%
Unamortized debt discount and issuance costs	$ 7
Senior Notes \| 2.5% Senior Notes due 2029
Debt Instrument [Line Items]
Long-term debt	$ 495	495
Stated interest rate (as a percent)	2.50%		2.50%
Unamortized debt discount and issuance costs	$ 5
Senior Notes \| 6.55% Senior Notes due 2037
Debt Instrument [Line Items]
Long-term debt	$ 294	294
Stated interest rate (as a percent)	6.55%
Unamortized debt discount and issuance costs	$ 3
Senior Notes \| 4.5% Senior Notes due 2048
Debt Instrument [Line Items]
Long-term debt	$ 490	490
Stated interest rate (as a percent)	4.50%			4.50%
Unamortized debt discount and issuance costs	$ 10
Senior Notes \| 3.25% Senior Notes due 2049
Debt Instrument [Line Items]
Long-term debt	$ 589	$ 589
Stated interest rate (as a percent)	3.25%		3.25%
Unamortized debt discount and issuance costs	$ 11