Revenue Recognition - Summary of Disaggregated Net Sales (Detail) - USD ($) $ in Thousands	3 Months Ended												12 Months Ended
	Dec. 28, 2019	Sep. 28, 2019	Jun. 29, 2019	Mar. 30, 2019	Dec. 29, 2018	[1]	Sep. 29, 2018	[1]	Jun. 30, 2018	[1]	Mar. 31, 2018	[1]	Dec. 28, 2019	Dec. 29, 2018	Dec. 30, 2017
Disaggregation Of Revenue [Line Items]
Net Sales	$ 239,567	$ 253,796	$ 254,175	$ 243,791	$ 260,341		$ 247,954		$ 238,147		$ 227,262		$ 991,329	$ 973,705	$ 903,221
U.S. Customers [Member]
Disaggregation Of Revenue [Line Items]
Net Sales													929,908	913,181	847,394
Non-U.S. Customers [Member]
Disaggregation Of Revenue [Line Items]
Net Sales													61,421	60,524	55,827
Powertrain [Member]
Disaggregation Of Revenue [Line Items]
Net Sales													395,975	393,979	374,372
Chassis [Member]
Disaggregation Of Revenue [Line Items]
Net Sales													297,350	278,584	238,239
Automotive Body [Member]
Disaggregation Of Revenue [Line Items]
Net Sales													251,506	256,344	245,869
Hardware [Member]
Disaggregation Of Revenue [Line Items]
Net Sales													$ 46,498	$ 44,798	$ 44,741

[1] Quarterly information does not add to year to date information due to rounding