Segment Information - Net Sales by Major Product Line (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 30, 2017	Dec. 31, 2016	Dec. 26, 2015
Revenue from External Customer [Line Items]
Net sales	$ 2,266,073	$ 2,055,622	$ 2,100,002
Tube and Fittings [Member]
Revenue from External Customer [Line Items]
Net sales	1,260,105	1,072,242	1,053,761
Brass Rod and Forgings [Member]
Revenue from External Customer [Line Items]
Net sales	450,063	371,237	436,456
OEM Components, Tube & Assemblies [Member]
Revenue from External Customer [Line Items]
Net sales	272,567	327,327	342,651
Valves and Plumbing Specialties [Member]
Revenue from External Customer [Line Items]
Net sales	200,409	209,217	198,012
Other [Member]
Revenue from External Customer [Line Items]
Net sales	$ 82,929	$ 75,599	$ 69,122