Income Taxes (Narrative) (Details) (USD $)	3 Months Ended				12 Months Ended			3 Months Ended	9 Months Ended
	Dec. 31, 2014 country	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2014 country	Dec. 31, 2013	Dec. 31, 2012	Mar. 31, 2013	Sep. 30, 2014	Dec. 31, 2011	Jul. 31, 2014
Income Tax Contingency [Line Items]
Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense					$ 53,000,000	$ 21,000,000	$ 21,000,000
Tax Credit Carryforward, Amount	103,000,000				103,000,000
Provision for Income Taxes					(284,000,000)	(144,000,000)	(462,000,000)
Income (Loss) from Continuing Operations before Income Taxes, Extraordinary Items, Noncontrolling Interest					(255,000,000)	(170,000,000)	(288,000,000)
Asset Impairment Charges	(40,000,000)		(143,000,000)
Impairment of Long-Lived Assets Held-for-use	(352,000,000)				(495,000,000)	0	0
Long-Lived Assets Impairment					495,000,000	0	0
Loss contingency accrual, provision					0	153,000,000	100,000,000
Gain (Loss) on Sale of Interest in Projects						(299,000,000)
Bad debt expense					27,000,000	102,000,000	22,000,000
Gain (Loss) on Disposition of Business	311,000,000				349,000,000	24,000,000	28,000,000
Goodwill impairment loss	40,000,000		(125,000,000)		66,000,000		589,000,000
Impairment Of Equity Method Investments							204,000,000
Restructuring Charges	58,000,000	154,000,000	59,000,000	70,000,000	331,000,000	0	0
Number of countries operated in (over 100 countries)	100				100
Undistributed Earnings of Foreign Subsidiaries	3,000,000,000				3,000,000,000
Operating Loss Carryforwards	2,600,000,000				2,600,000,000
Significant (Increase) Decrease in Unrecognized Tax Benefits is Reasonably Possible, Estimated Range of Change, Upper Bound	24,000,000				24,000,000
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued	58,000,000				58,000,000	121,000,000	142,000,000
United States [Member]
Income Tax Contingency [Line Items]
Tax Credit Carryforward, Amount	85,000,000				85,000,000
Operating Loss Carryforwards	239,000,000				239,000,000
Iraq [Member]
Income Tax Contingency [Line Items]
Valuation allowance	172,000,000				172,000,000
Trade Sanctions [Member]
Income Tax Contingency [Line Items]
Loss contingency accrual, provision							100,000,000
Research Tax Credit Carryforward [Member] | United States [Member]
Income Tax Contingency [Line Items]
Tax Credit Carryforward, Amount	28,000,000				28,000,000
Foreign Tax Credit Carryforward [Member] | United States [Member]
Income Tax Contingency [Line Items]
Tax Credit Carryforward, Amount	57,000,000				57,000,000
Venezuelan Bolivar [Member]
Income Tax Contingency [Line Items]
Currency devaluation expense					245,000,000	100,000,000		100,000,000
Amount Recognized in Income Due to Inflationary Accounting, Net of Tax	(245,000,000)				(252,000,000)	(94,000,000)
Valuation Allowance of Deferred Tax Assets [Member]
Income Tax Contingency [Line Items]
Valuation allowance	732,000,000				732,000,000	554,000,000	317,000,000			201,000,000
Valuation Allowance of Deferred Tax Assets [Member] | Iraq [Member]
Income Tax Contingency [Line Items]
Valuation allowance						134,000,000
Operating Segments [Member]
Income Tax Contingency [Line Items]
Bad debt expense					72,000,000	98,000,000
Europe/Sub-Sahara Africa/Russia [Member]
Income Tax Contingency [Line Items]
Impairment of Long-Lived Assets Held-for-use	(28,000,000)
Bad debt expense						10,000,000
Goodwill impairment loss	13,000,000		77,000,000		39,000,000
Restructuring Charges					36,000,000
Goodwill Impairment including assets held for sale [Member]
Income Tax Contingency [Line Items]
Goodwill impairment loss					(161,000,000)
Pipeline and Specialty Services Business [Member]
Income Tax Contingency [Line Items]
Gain (Loss) on Disposition of Business									49,000,000
Cash disposed to sell disposal group		245,000,000							245,000,000
Land Drilling and Workover Rig Operations [Member]
Income Tax Contingency [Line Items]
Long-Lived Assets Impairment			143,000,000
Gain (Loss) on Disposition of Business			(15,000,000)
Cash disposed to sell disposal group											486,000,000
Goodwill impairment loss			$ 121,000,000