Revenue Recognition (Changes In Contract Assets And Contract Liabilities) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Revenue Recognition [Abstract]
Contract current liabilities, Beginning balance	$ 27	$ 27
Contract current liabilities, Revenue recognized included in opening contract balance	(9)	(9)
Contract current liabilities, Credits granted, excluding amounts recognized as revenue	10	9
Contract current liabilities, Reclassified between current and concurrent	2
Contract current liabilities, Ending balance	30	27
Contract noncurrent liabilities, Beginning balance	17	11
Contract noncurrent liabilities, Revenue recognized included in opening contract balance	(3)	(3)
Contract noncurrent liabilities, Credits granted, excluding amounts recognized as revenue	5	5
Contract noncurrent liabilities, Reclassified between current and concurrent	(2)
Contract noncurrent liabilities, Ending balance	$ 17	$ 13