Financial Instruments (Narrative) (Details) - Interest Rate Swaps - USD ($) $ in Millions	Jun. 30, 2018	Jun. 30, 2017
Fair Value Hedging
Derivative [Line Items]
Derivative, notional amount	$ 2,313	$ 1,813
Designated as Hedging Instrument | Fair Value Hedging
Derivative [Line Items]
Derivative, notional amount	1,050	700
Derivatives, terminated notional amounts		600
Derivatives, matured notional amounts	$ 550	250
Designated as Hedging Instrument | Cash Flow Hedging
Derivative [Line Items]
Derivative, notional amount		700
Derivatives, terminated notional amounts		$ 1,000