Borrowings (Schedule of Long-term Debt) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Debt Disclosure [Abstract]
Short-term commercial paper borrowings	$ 1,494.2	$ 498.9
0.15 to 7.13 percent long-term notes (due 2022-2059)	13,638.5	9,640.8
Other long-term debt	12.9	10.1
Unamortized debt issuance costs	(73.6)	(28.4)
Fair value adjustment on hedged long-term notes	245.2	177.2
Total debt	15,317.2	10,298.6
Less current portion	(1,499.3)	(1,102.2)
Long-term debt	$ 13,817.9	$ 9,196.4
Minimum
Debt Instrument [Line Items]
Stated interest rate	0.15%
Maximum
Debt Instrument [Line Items]
Stated interest rate	7.13%

Fair value adjustment to carrying value of long term debt to arrive at total fair value.

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Carrying value as of the balance sheet date of short-term borrowings using unsecured obligations issued by banks, corporations and other borrowers to investors. The maturities of these money market securities generally do not exceed 270 days.

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Amount of short-term debt and current maturity of long-term debt and capital lease obligations due within one year or the normal operating cycle, if longer.

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

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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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Represents the aggregate of total long-term debt, including current maturities and short-term debt.

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Amount after unamortized (discount) premium and debt issuance costs of long-term debt classified as noncurrent and excluding amounts to be repaid within one year or the normal operating cycle, if longer. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Including the current and noncurrent portions, aggregate carrying amount of all types of notes payable, as of the balance sheet date, with initial maturities beyond one year or beyond the normal operating cycle, if longer.

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Amount of long-term notes payable classified as other.

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The remaining balance of debt issuance expenses that were capitalized and are being amortized against income over the lives of the respective bond issues. This does not include the amounts capitalized as part of the cost of the utility plant or asset.

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