Commitments and Contingencies - Additional Information (Detail)				9 Months Ended	12 Months Ended
	Oct. 21, 2019 Plaintiff	Oct. 18, 2019 Plaintiff	Mar. 08, 2016 USD ($)	Sep. 30, 2019 USD ($) Plaintiff	Dec. 31, 2018 USD ($)	Oct. 20, 2019 USD ($)	Jun. 30, 2019 USD ($)
Commitments And Contingencies Disclosure [Line Items]
Loss contingency estimate				$ 225,000,000
Potential environmental liabilities				0
Reduction in Transaction Price [Member]
Commitments And Contingencies Disclosure [Line Items]
Loss contingency estimate				$ 50,000,000
Cost Reimbursable Projects [Member]
Commitments And Contingencies Disclosure [Line Items]
Loss contingency, damages amount			$ 4,500,000,000
Asserted claims against customer			$ 250,000,000
Consolidated Joint Venture Projects [Member]
Commitments And Contingencies Disclosure [Line Items]
Asserted claims against customer					$ 103,000,000
Net of amounts owned to joint venture					$ 78,600,000
Reserve for estimated project losses							$ 55,000,000
Reserve for estimated project losses at joint venture level							85,000,000
Mercury Litigation [Member]
Commitments And Contingencies Disclosure [Line Items]
Number of plaintiffs | Plaintiff				54
Mercury Litigation [Member] | Subsequent Event [Member]
Commitments And Contingencies Disclosure [Line Items]
Number of plaintiffs | Plaintiff		54
Number of plaintiffs set for the trials of the claims | Plaintiff	4
Chicago Bridge & Iron Company N.V. Securities Litigation [Member]
Commitments And Contingencies Disclosure [Line Items]
Loss contingency accrual liability amount							0
Gotham Diversified Neutral Master Fund, LP, et al. v. Chicago Bridge & Iron Company N.V. et al., and Appaloosa Investment L.P., et al., v. Chicago Bridge & Iron Company N.V., et al. [Member]
Commitments And Contingencies Disclosure [Line Items]
Loss contingency accrual liability amount							0
Daniel Cohen, et al. v. Chicago Bridge & Iron Company, N.V., et al. [Member]
Commitments And Contingencies Disclosure [Line Items]
Loss contingency accrual liability amount							0
Edwards v. McDermott International, Inc., et al.. [Member]
Commitments And Contingencies Disclosure [Line Items]
Loss contingency accrual liability amount							$ 0
Saudi Arabia Customs Audit [Member] | Subsequent Event [Member]
Commitments And Contingencies Disclosure [Line Items]
Loss contingency accrual liability amount						$ 0
Loss contingency estimate						$ 47,600,000