Supplemental Cash Flow Disclosures (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Supplemental Cash Flow Information [Abstract]
Interest paid, net of amounts capitalized		$ 1,715	$ 1,673	$ 1,764
Income Taxes Paid, Net	[1]	(540)	(1,016)	(1,666)
Related Party Transaction, Cash Received for Income Taxes, Net		600	1,100	1,781
Capital Expenditures Incurred but Not yet Paid		653	547	718
Capital Expenditures Incurred Deferred Payments		$ 100	$ 0	$ 0

[1] Includes $636 million, $1.1 billion and $1.8 billion of income taxes received from Berkshire Hathaway in 2017, 2016 and 2015, respectively.