Investments In and Advances To Affiliates - Summarized Financial Information (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Jan. 01, 2020
Schedule of Equity Method Investments [Line Items]
Revenue	$ 2,770	$ 3,036	$ 2,700	$ 2,635	$ 2,560	$ 2,545	$ 2,217	$ 2,338	$ 11,141	$ 9,660	$ 10,189
Operating margin	559	760	728	664	906	756	524	507	2,711	2,693	2,349
Net income (loss)	(1,330)	$ 485	$ (77)	$ (29)	401	$ (481)	$ 3	$ 229	(951)	152	478
Assets, Current	5,356				5,414				5,356	5,414
Liabilities, Current	4,732				5,362				4,732	5,362
Liabilities, Noncurrent	22,407				23,649				22,407	23,649
Stockholders' Equity Attributable to Noncontrolling Interest	1,769				2,086				1,769	2,086	2,233	$ 2,217
Stockholders' Equity Attributable to Parent	2,798				2,634				2,798	2,634
Undistributed Earnings Of Minority Owned Affiliates Included In Retained Earnings	169								169
Distributions Received From Minority Owned Affiliates									25	14	23
Basis Difference Between Carrying Amount And Investment	37								37
Minority Owned Affiliates
Schedule of Equity Method Investments [Line Items]
Revenue									1,316	1,880	1,122
Operating margin									(53)	213	124
Net income (loss)									(242)	(538)	(724)
Assets, Current	1,180				1,017				1,180	1,017
Assets, Noncurrent	6,497				6,230				6,497	6,230
Liabilities, Current	1,414				1,294				1,414	1,294
Liabilities, Noncurrent	3,602				3,671				3,602	3,671
Stockholders' Equity Attributable to Noncontrolling Interest	1				0				1	0
Stockholders' Equity Attributable to Parent	2,660				2,282				2,660	2,282
Majority Owned Affiliates
Schedule of Equity Method Investments [Line Items]
Revenue									1	1	49
Operating margin									(1)	(3)	(5)
Net income (loss)									(3)	(4)	$ (7)
Assets, Current	868				159				868	159
Assets, Noncurrent	25				886				25	886
Liabilities, Current	859				121				859	121
Liabilities, Noncurrent	60				981				60	981
Stockholders' Equity Attributable to Noncontrolling Interest	0				0				0	0
Stockholders' Equity Attributable to Parent	$ (26)				$ (57)				$ (26)	$ (57)