Business, Basis of Presentation and Significant Accounting Policies (Narrative) (Details) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017 USD ($)	Jun. 30, 2016	Jun. 30, 2017 USD ($) segment	Jun. 30, 2016	Dec. 31, 2016 USD ($)
Segment Reporting, Disclosure of Entity's Reportable Segments [Abstract]
Number of reportable segments | segment			5
Revenue Recognition [Line Items]
Unapproved change orders, description			The Company may incur costs subject to change orders, whether approved or unapproved by the customer, and/or claims related to certain contracts. Management determines the probability that such costs will be recovered based upon engineering studies and legal opinions, past practices with the customer, specific discussions, correspondence or preliminary negotiations with the customer. The Company treats such costs as a cost of contract performance in the period incurred if it is not probable that the costs will be recovered, and defers costs or recognizes revenue up to the amount of the related cost if it is probable that the contract price will be adjusted and can be reliably estimated. As of June 30, 2017 and December 31, 2016, the Company had approximately $19 million and $17 million, respectively, of change orders and/or claims that had been included as contract price adjustments on certain contracts that were in the process of being resolved in the normal course of business, including through negotiation, arbitration and other proceedings. These contract price adjustments, which are included within costs and earnings in excess of billings or billed accounts receivable, as appropriate, represent management’s best estimate of contract revenue that has been earned and that management believes is probable of collection. As of both June 30, 2017 and December 31, 2016, these change orders were primarily related to contracts in the Oil and Gas segment. The Company actively engages in substantive meetings with its customers to complete the final approval process, and generally expects these processes to be completed within one year. The amounts ultimately realized upon final acceptance by its customers could be higher or lower than such estimated amounts.
Accounts Receivable [Member]
Revenue Recognition [Line Items]
Unapproved change orders, expected to be billed and collected within one year, amount (in dollars) | $	$ 19		$ 19		$ 17
Maximum [Member]
Revenue Recognition [Line Items]
Fixed price contract, percentage-of-completion method, term within which generally completed (in years)			1 year
Change order approval process, term within which expected to be completed (in years)			1 year
Contracts Accounted for under Percentage-of-Completion [Member] | Maximum [Member]
Revenue Recognition [Line Items]
Change in accounting estimate, percentage-of-completion projects, financial effect on project profit, percentage			5.00%	5.00%
Master Service and Other Service Agreements [Member] | Concentration Risk from Type of Arrangement [Member] | Revenue [Member]
Revenue Recognition [Line Items]
Concentration risk, percentage of total	31.00%	45.00%	37.00%	47.00%