Taxation (Provision For Income Taxes) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Examination [Line Items]
Income (Loss) from Continuing Operations before Income Taxes, Domestic	$ 766	$ 469	$ 404
Income (Loss) from Continuing Operations before Income Taxes, Foreign	4,184	2,827	3,083
Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	4,950	3,296	3,487
Current tax expense	824	304	481
Deferred tax expense	(9)	158	153
Provision for income taxes	815	462	634
Domestic Tax Authority [Member]
Income Tax Examination [Line Items]
Current tax expense	97	38	31
Deferred tax expense	(27)	4	9
Foreign Tax Authority [Member]
Income Tax Examination [Line Items]
Current tax expense	727	266	450
Deferred tax expense	$ 18	$ 154	$ 144