Note 9 - Segment Information - Sales by Product Line (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Sales	$ 585	$ 942	$ 1,981	$ 2,896
Line Pipe [Member]
Sales	63	153	243	468
Carbon Fittings and Flanges [Member]
Sales	76	145	264	456
Carbon Pipe, Fittings and Flanges [Member]
Sales	139	298	507	924
Valves, Automation, Measurement and Instrumentation [Member]
Sales	230	362	802	1,125
Gas Products [Member]
Sales	131	147	379	425
Stainless Steel and Alloy Pipe and Fittings [Member]
Sales	29	43	96	135
General Oilfield Products [Member]
Sales	$ 56	$ 92	$ 197	$ 287