Segment Information - Net Sales by Major Product Line (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 28, 2019	Sep. 29, 2018	Sep. 28, 2019	Sep. 29, 2018
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	$ 608,602	$ 645,958	$ 1,886,777	$ 1,948,791
Operating Segments [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	617,298	650,853	1,904,164	1,963,458
Operating Segments [Member] | Piping Systems [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	390,917	410,525	1,193,274	1,294,672
Operating Segments [Member] | Industrial Metals [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	135,443	158,709	434,037	511,932
Operating Segments [Member] | Climate [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	90,938	81,619	276,853	156,854
Operating Segments [Member] | Tube and fittings [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	320,789	340,269	986,783	1,077,525
Operating Segments [Member] | Tube and fittings [Member] | Piping Systems [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	320,789	340,269	986,783	1,077,525
Operating Segments [Member] | Tube and fittings [Member] | Industrial Metals [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	0	0	0	0
Operating Segments [Member] | Tube and fittings [Member] | Climate [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	0	0	0	0
Operating Segments [Member] | Brass rod and forgings [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	103,616	122,411	333,622	394,880
Operating Segments [Member] | Brass rod and forgings [Member] | Piping Systems [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	0	0	0	0
Operating Segments [Member] | Brass rod and forgings [Member] | Industrial Metals [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	103,616	122,411	333,622	394,880
Operating Segments [Member] | Brass rod and forgings [Member] | Climate [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	0	0	0	0
Operating Segments [Member] | OEM components, tube and assemblies [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	51,117	55,465	165,941	174,874
Operating Segments [Member] | OEM components, tube and assemblies [Member] | Piping Systems [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	7,059	7,618	21,786	22,128
Operating Segments [Member] | OEM components, tube and assemblies [Member] | Industrial Metals [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	11,724	12,292	37,613	41,956
Operating Segments [Member] | OEM components, tube and assemblies [Member] | Climate [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	32,334	35,555	106,542	110,790
Operating Segments [Member] | Valves and plumbing specialties [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	63,069	62,638	184,705	195,019
Operating Segments [Member] | Valves and plumbing specialties [Member] | Piping Systems [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	63,069	62,638	184,705	195,019
Operating Segments [Member] | Valves and plumbing specialties [Member] | Industrial Metals [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	0	0	0	0
Operating Segments [Member] | Valves and plumbing specialties [Member] | Climate [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	0	0	0	0
Operating Segments [Member] | Other products [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	78,707	70,070	233,113	121,160
Operating Segments [Member] | Other products [Member] | Piping Systems [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	0	0	0	0
Operating Segments [Member] | Other products [Member] | Industrial Metals [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	20,103	24,006	62,802	75,096
Operating Segments [Member] | Other products [Member] | Climate [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	58,604	46,064	170,311	46,064
Intersegment Sales [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	$ (8,696)	$ (4,895)	$ (17,387)	$ (14,667)