Income Taxes (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2020
Income Tax [Line Items]
Income tax expense (benefit)	$ (417)	$ (119)
Change in deferred tax valuation allowance	$ 108
Valuation allowance against deferred tax assets, percent	100.00%
Increase in unrecognized tax benefits	$ 34
CARES Act [Member]
Income Tax [Line Items]
Income tax expense (benefit)	$ (96)
Scenario Forecast [Member] | CARES Act [Member]
Income Tax [Line Items]
Income tax expense (benefit)			$ (9)