Derivatives (Details 2-Fair Value Hedges) - Debentures Due 2018 [Member] - Not Designated as Hedging Instrument [Member] - Interest Rate Swap [Member] $ in Millions	Mar. 31, 2017 USD ($)
Derivative [Line Items]
Aggregate Notional Amount - Interest Rate Swap Agreements	$ 750
Derivative, Fixed Interest Rate	1.57%

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.

No definition available.

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