Fair Value Measurements Level Three Liabilities (Details)	9 Months Ended
	Mar. 31, 2017 USD ($)
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value at July 1, 2016	$ 155,000,000
Net realized gain	(34,000,000)
Redemptions	(129,000,000)
Net unrealized loss	10,000,000
Fair value at March 31, 2017	2,000,000
2017 Exchange Option [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value at July 1, 2016	87,000,000
Net realized gain	(3,000,000)
Redemptions	(83,000,000)
Net unrealized loss	0
Fair value at March 31, 2017	1,000,000
2020 Exchange Option [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value at July 1, 2016	68,000,000
Net realized gain	(31,000,000)
Redemptions	(46,000,000)
Net unrealized loss	10,000,000
Fair value at March 31, 2017	$ 1,000,000