KBR Separation (Details) (USD $) In Millions, unless otherwise specified	1 Months Ended	3 Months Ended		12 Months Ended			3 Months Ended
	Sep. 30, 2014	Dec. 31, 2014	Sep. 30, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Mar. 31, 2013
Loss Contingencies [Line Items]
KBR indemnities and guarantees		$ 0		$ 0
Payment made for KBR obligation	1,100	395		0	219	0
KBR Settlement_Aggregate Amount			81
KBR Settlement_InitIal Payment Amount			12	25
KBR Settlement_Contingent Payment to be received			19
KBR Settlement_Total of Installment Payments	50		50
Number of Payment Installments_KBR	4		4
KBR Settlement Agreement, Net of Income Tax			63
Barracuda-Caratinga arbitration
Loss Contingencies [Line Items]
Payment made for KBR obligation							$ 219