Segment Information - Net Sales by Major Product Line (Details) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 29, 2018	Sep. 30, 2017		Sep. 29, 2018	Sep. 30, 2017
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	$ 645,958	$ 550,363	[1]	$ 1,948,791	$ 1,742,549	[1]
Operating Segments [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	650,853	564,144		1,963,458	1,761,019
Operating Segments [Member] | Piping Systems [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	410,525	384,078		1,294,672	1,205,697
Operating Segments [Member] | Industrial Metals [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	158,709	147,578		511,932	451,919
Operating Segments [Member] | Climate [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	81,619	32,488		156,854	103,403
Operating Segments [Member] | Tube and fittings [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	340,269	319,115		1,077,525	945,914
Operating Segments [Member] | Tube and fittings [Member] | Piping Systems [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	340,269	319,115		1,077,525	945,914
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	122,411	112,592		394,880	346,555
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	122,411	112,592		394,880	346,555
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	55,465	52,501		174,874	229,198
Operating Segments [Member] | OEM components, tube and assemblies [Member] | Piping Systems [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	7,618	6,962		22,128	86,642
Operating Segments [Member] | OEM components, tube and assemblies [Member] | Industrial Metals [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	12,292	13,051		41,956	39,153
Operating Segments [Member] | OEM components, tube and assemblies [Member] | Climate [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	35,555	32,488		110,790	103,403
Operating Segments [Member] | Valves and plumbing specialties [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	62,638	58,001		195,019	173,141
Operating Segments [Member] | Valves and plumbing specialties [Member] | Piping Systems [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	62,638	58,001		195,019	173,141
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	70,070	21,935		121,160	66,211
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	24,006	21,935		75,096	66,211
Operating Segments [Member] | Other products [Member] | Climate [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	46,064	0		46,064	0
Intersegment Sales [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	$ (4,895)	$ (13,781)		$ (14,667)	$ (18,470)

[1] The Condensed Consolidated Statements of Income for the quarter and nine months ended September 30, 2017 have been adjusted to reflect the adoption of ASU 2017-07, Compensation - Retirement Benefits (Topic 715): Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost. The components of net periodic benefit cost (income) other than the service cost component are included in other income (expense), net in the Condensed Consolidated Statements of Income. Refer to Note 1 for further discussion.