Business Segments - Net Sales and Percentage of Consolidated Net Sales (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Concentration Risk [Line Items]
Net sales	$ 728,271	$ 764,850	$ 496,259	$ 531,694	$ 750,212	$ 704,134	$ 679,130	$ 619,163	$ 2,521,074	$ 2,752,639	$ 2,808,062
Customer Concentration Risk | American Tire Distributors, Inc. | Net Sales
Concentration Risk [Line Items]
Net sales									$ 329,631	$ 311,559	$ 310,070
Consolidated Net Sales									13.00%	11.00%	11.00%