Goodwill and Other Intangible Assets - Schedule of Project Related Intangibles (Parenthetical) (Detail) - USD ($) $ in Millions	3 Months Ended						12 Months Ended
	Dec. 31, 2018		Sep. 30, 2018	[1]	Jun. 30, 2018	[1]	Dec. 31, 2018
Finite Lived Intangible Assets [Line Items]
Other intangibles amortization	$ 27	[1]	$ 25		$ 10		$ 62
Project Related Intangibles [Member]
Finite Lived Intangible Assets [Line Items]
Other intangibles amortization							79
Amortization expense for intangible assets, in 2019	33						33
Amortization expense for intangible assets, in 2020	23						23
Amortization expense for intangible assets, in 2021	5						5
Amortization expense for intangible assets, in 2022	8						8
Amortization expense for intangible assets, in 2023	7						7
Inventory Related Intangibles [Member]
Finite Lived Intangible Assets [Line Items]
Other intangibles amortization							79
Amortization expense for intangible assets, in 2019	33						33
Amortization expense for intangible assets, in 2020	23						23
Amortization expense for intangible assets, in 2021	5						5
Amortization expense for intangible assets, in 2022	8						8
Amortization expense for intangible assets, in 2023	$ 7						$ 7

[1] Represents amortization of other intangible assets acquired in the Combination. See Note 9, Goodwill and Other Intangible Assets, for further discussion.