Fair Value Measurements Narrative (Details) - Recurring - USD ($) $ in Millions	Sep. 30, 2018	Jun. 30, 2018
Assets:
Cash equivalents		$ 200
Other investments	$ 120	117
Liabilities:
Derivative Assets (Liabilities), at Fair Value, Net	(89)	(76)
Level 1
Assets:
Cash equivalents		200
Other investments	120	117
Liabilities:
Derivative Assets (Liabilities), at Fair Value, Net	0	0
Level 2
Assets:
Cash equivalents		0
Other investments	0	0
Liabilities:
Derivative Assets (Liabilities), at Fair Value, Net	(89)	(76)
Level 3
Assets:
Cash equivalents		0
Other investments	0	0
Liabilities:
Derivative Assets (Liabilities), at Fair Value, Net	$ 0	$ 0