Accounts Receivable (Details) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Accounts, Notes, Loans and Financing Receivable [Line Items]
Account receivable, current	$ 773	$ 726
Trade Accounts Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Account receivable, current	734	676
Retainage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Account receivable, current	39	50
Technology and Consulting [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Account receivable, current	68	51
Technology and Consulting [Member] \| Trade Accounts Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Account receivable, current	68	51
Technology and Consulting [Member] \| Retainage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Account receivable, current	0	0
Engineering and Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Account receivable, current	650	583
Engineering and Construction [Member] \| Trade Accounts Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Account receivable, current	615	538
Engineering and Construction [Member] \| Retainage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Account receivable, current	35	45
Government Services [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Account receivable, current	55	89
Government Services [Member] \| Trade Accounts Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Account receivable, current	51	84
Government Services [Member] \| Retainage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Account receivable, current	4	5
Other Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Account receivable, current	0	3
Other Segment [Member] \| Trade Accounts Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Account receivable, current	0	3
Other Segment [Member] \| Retainage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Account receivable, current	0	0
Non-strategic Business [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Account receivable, current	77	121
Non-strategic Business [Member] \| Trade Accounts Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Account receivable, current	56	73
Non-strategic Business [Member] \| Retainage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Account receivable, current	21	48
Operating Segments [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Account receivable, current	850	847
Operating Segments [Member] \| Trade Accounts Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Account receivable, current	790	749
Operating Segments [Member] \| Retainage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Account receivable, current	60	98
Other Assets [Member] \| Non-strategic Business [Member] \| Retainage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable, non current	$ 28	$ 14