Impairments (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended			12 Months Ended
	Dec. 31, 2016	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Assets held for sale
Aggregate loss on impairment of assets held for sale				$ 41	$ 700
Assets held and used
Loss associated with impairment	$ 52	$ 668	$ 507
Impairment of certain corporate assets					52
Goodwill, Impaired [Abstract]
Goodwill impairment loss						$ 3,000
Loss on impairment of goodwill, tax effect						0
Loss on impairment of goodwill attributable to controlling interest						$ 2,900
Loss on impairment of goodwill attributable to controlling interest per diluted share						$ 8.02
Loss on impairment of goodwill per diluted share from continuing operations						$ 8.02
Loss on impairment of goodwill attributable to noncontrolling interest						$ 74
Deepwater Floater asset group
Assets held and used
Loss associated with impairment				$ 52	507	788
Loss associated with impairment, net of tax					$ 481	$ 693
Loss associated with impairment per diluted share				$ 0.14	$ 1.31	$ 1.91
Midwater Floater asset group
Assets held and used
Loss associated with impairment					$ 668
Loss associated with impairment, net of tax					$ 654
Loss associated with impairment per diluted share					$ 1.78
Construction in Progress
Assets held and used
Loss associated with impairment					$ 52
Construction in Progress | Deepwater Floater asset group
Assets held and used
Impairment of certain corporate assets					41
Construction in Progress | Midwater Floater asset group
Assets held and used
Impairment of certain corporate assets					11
Rig sales | Assets held for sale
Assets held for sale
Aggregate loss on impairment of assets held for sale				$ 41	700	$ 268
Aggregate loss on impairment of assets held for sale, net of tax				$ 39	$ 585	$ 221
Aggregate loss on impairment of assets per diluted share				$ 0.10	$ 1.60	$ 0.60