Segment Information - Summary of Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Apr. 01, 2017	Apr. 02, 2016
Summary of segment information [Abstract]
Net sales	$ 577,920	$ 532,809
Cost of goods sold	488,427	446,642
Depreciation and amortization	8,355	8,920
Selling, general, and administrative expense	35,531	35,780
Operating income	45,607	41,467
Interest expense	(2,531)	(1,848)
Other income, net	551	245
Income before income taxes	43,627	39,864
Operating Segments [Member] | Piping Systems [Member]
Summary of segment information [Abstract]
Net sales	398,775	368,890
Cost of goods sold	344,646	313,792
Depreciation and amortization	5,342	5,649
Selling, general, and administrative expense	18,421	18,290
Operating income	30,366	31,159
Operating Segments [Member] | Industrial Metals [Member]
Summary of segment information [Abstract]
Net sales	149,837	134,521
Cost of goods sold	124,043	109,229
Depreciation and amortization	1,898	2,135
Selling, general, and administrative expense	3,230	3,245
Operating income	20,666	19,912
Operating Segments [Member] | Climate [Member]
Summary of segment information [Abstract]
Net sales	34,279	30,706
Cost of goods sold	25,564	23,705
Depreciation and amortization	629	599
Selling, general, and administrative expense	2,476	2,523
Operating income	5,610	3,879
Corporate and Eliminations [Member]
Summary of segment information [Abstract]
Net sales	(4,971)	(1,308)
Cost of goods sold	(5,826)	(84)
Depreciation and amortization	486	537
Selling, general, and administrative expense	11,404	11,722
Operating income	$ (11,035)	$ (13,483)