Business Segments - Schedule of Comparison of Approximate Sales Mix in Principal Product Categories (Detail) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Entity Wide Portfolio Carrying Amount Major Customer [Line Items]
Total Revenues	$ 764	$ 822	$ 777	$ 764	$ 669	$ 697	$ 651	$ 631	$ 3,127	$ 2,648	$ 2,107
Drilling and Production [Member]
Entity Wide Portfolio Carrying Amount Major Customer [Line Items]
Total Revenues									691	625	496
Pipe [Member]
Entity Wide Portfolio Carrying Amount Major Customer [Line Items]
Total Revenues									587	418	287
Valves [Member]
Entity Wide Portfolio Carrying Amount Major Customer [Line Items]
Total Revenues									664	541	374
Fittings and Flanges [Member]
Entity Wide Portfolio Carrying Amount Major Customer [Line Items]
Total Revenues									523	419	350
Mill Tool, MRO, Safety and Other [Member]
Entity Wide Portfolio Carrying Amount Major Customer [Line Items]
Total Revenues									$ 662	$ 645	$ 600