Lease Obligations - Additional Information (Detail) - Amazon Pipe-lay and Construction Vessel [Member] - USD ($) $ in Millions	Jul. 27, 2018	Mar. 31, 2020	Dec. 31, 2019
Lessee Lease Description [Line Items]
Capital expenditure expected	$ 80
Property, plant and equipment, net		$ 49	$ 49
Accumulated amortization,net		6	6
Finance lease liability		$ 44	$ 46
Minimum [Member]
Lessee Lease Description [Line Items]
Cost of modification including project management and other fees and expenses	295
Maximum [Member]
Lessee Lease Description [Line Items]
Cost of modification including project management and other fees and expenses	$ 325