Debt - Schedule of Uncommitted Bilateral Credit Facilities and Surety Bond Arrangements (Detail) - Uncommitted Bilateral Letter of Credit Facilities and Surety Bond Arrangements [Member] - USD ($)		Sep. 30, 2018	Dec. 31, 2017
Bank Guarantee and Bilateral Letter of Credit [Member]
Debt Instrument [Line Items]
Available capacity under current credit agreement	[1]	$ 1,609,000,000	$ 725,000,000
Letters of credit utilized	[1]	928,000,000	572,000,000
Surety Bonds [Member]
Debt Instrument [Line Items]
Available capacity under current credit agreement	[2]	828,000,000	300,000,000
Letters of credit utilized	[2]	$ 419,000,000	49,000,000
Bilateral Arrangements to Issue Cash Collateralized Letters Of Credit [Member]
Debt Instrument [Line Items]
Available capacity under current credit agreement			175,000,000
Letters of credit utilized			$ 18,000,000

[1] Approximately $175 million of this capacity is available only upon provision of an equivalent amount of cash collateral.

[2] Excludes approximately $403 million of surety bonds maintained on behalf of CB&I’s former Capital Services Operations, which were sold to CSVC Acquisition Corp (“CSVC”) in June 2017. We also continue to maintain guarantees on behalf of CB&I’s former Capital Services Operations business in support of approximately $82 million of RPOs. We are entitled to an indemnity from CSVC for both the surety bonds and guarantees.