Income Taxes (Narrative) (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2018
(Provision) Benefit for Income Taxes	$ (25,000,000)	$ (692,000,000)	$ (75,000,000)	$ (489,000,000)
Income (loss) before income taxes	(226,000,000)	(1,084,000,000)	(784,000,000)	(2,340,000,000)
Asset Impairment Charges		436,000,000	0	436,000,000
Inventory Charges			66,000,000	213,000,000
Production Related Impairments or Charges		198,000,000
Allowance for Doubtful Accounts Receivable, Write-offs		62,000,000		62,000,000
Other Asset Impairment Charges		44,000,000		121,000,000
Effective Income Tax Rate Reconciliation, Repatriation of Foreign Earnings, Amount		137,000,000
Bond Tender Premium	0	0	0	(78,000,000)
Financing Receivable, Allowance for Credit Losses, Write-downs				84,000,000
Foreign exchange related charges	$ 0	0	$ 0	31,000,000
Pressure Pumping Related Charges				20,000,000
Supply Agreement Charges related to Non-Core Business Divestiture				15,000,000
Deferred Tax Assets, Valuation Allowance		$ 526,000,000		526,000,000
Forecast
Uncertain tax positions, estimated for next twelve months					$ 10,000,000
SEC Settlement
Gain (loss) related to litigation settlement				$ (140,000,000)