Acquisition and Disposition Transactions - Summary of Loss on APP Sale Included in Loss on Asset Disposals (Detail) - USD ($) $ in Millions		3 Months Ended		12 Months Ended
	Jun. 27, 2019	Dec. 31, 2019	Jun. 30, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Liabilities
Sale proceeds (net of transaction costs of $2)				$ 83	$ 69	$ 56
Loss on net assets sold		$ (2)	$ (102)	$ 104	$ 3	$ (2)
Alloy Piping Products [Member]
Assets
Inventory	$ 69
Property and equipment	25
Goodwill	90
Other assets	11
Assets sold	195
Liabilities
Accounts payable	8
Other liabilities	3
Liabilities sold	11
Net assets sold	184
Sale proceeds (net of transaction costs of $2)	83
Loss on net assets sold	$ 101