Revenue Recognition (Changes In Contract Assets And Contract Liabilities) (Details) - USD ($) $ in Millions	2 Months Ended	4 Months Ended	6 Months Ended
	Jun. 30, 2021	Apr. 30, 2021	Jun. 30, 2022
Successor [Member]
Contract current liabilities, Beginning balance	$ 15		$ 27
Contract current liabilities, Revenue recognized included in opening contract balance	(4)		(20)
Contract current liabilities, Cash received, excluding amounts recognized as revenue	8
Contract current liabilities, Credits granted, excluding amounts recognized as revenue			18
Contract current liabilities, Reclassified between current and concurrent	(1)		2
Contract current liabilities, Ending balance	18	$ 15	27
Contract noncurrent liabilities, Beginning balance	1		11
Contract noncurrent liabilities, Revenue recognized included in opening contract balance	(1)		(5)
Contract noncurrent liabilities, Cash received, excluding amounts recognized as revenue	4
Contract noncurrent liabilities, Credits granted, excluding amounts recognized as revenue			11
Contract noncurrent liabilities, Reclassified between current and concurrent	1		(2)
Contract noncurrent liabilities, Ending balance	5	1	$ 15
Predecessor [Member]
Contract current assets, Beginning balance	2	6
Contract current assets, Revenue recognized included in opening contract balance		(4)
Contract current assets, Ending balance		2
Contract noncurrent assets, Beginning balance	9	9
Contract noncurrent assets, Ending balance		9
Contract current liabilities, Beginning balance	57	58
Contract current liabilities, Revenue recognized included in opening contract balance		(23)
Contract current liabilities, Cash received, excluding amounts recognized as revenue		22
Contract current liabilities, Ending balance		57
Contract noncurrent liabilities, Beginning balance	19	20
Contract noncurrent liabilities, Revenue recognized included in opening contract balance		(3)
Contract noncurrent liabilities, Cash received, excluding amounts recognized as revenue		2
Contract noncurrent liabilities, Ending balance		19
Fresh Start Adjustments [Member] | Predecessor [Member]
Contract current assets, Beginning balance	(2)
Contract current assets, Ending balance		(2)
Contract noncurrent assets, Beginning balance	(9)
Contract noncurrent assets, Ending balance		(9)
Contract current liabilities, Beginning balance	(42)
Contract current liabilities, Ending balance		(42)
Contract noncurrent liabilities, Beginning balance	(18)
Contract noncurrent liabilities, Ending balance		(18)
After Fresh Start Accounting Adjustments [Member] | Predecessor [Member]
Contract current liabilities, Beginning balance	15
Contract current liabilities, Ending balance		15
Contract noncurrent liabilities, Beginning balance	$ 1
Contract noncurrent liabilities, Ending balance		$ 1