Acquisitions - Summary of Pro Forma Information (Detail) - USD ($) $ / shares in Units, $ 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
Business Acquisition [Line Items]
Net sales, As reported	$ 2,291,315	$ 1,936,478	$ 1,968,735	$ 2,144,051	$ 2,297,156	$ 1,912,547	$ 1,836,021	$ 1,685,466	$ 8,340,579	$ 7,731,190	$ 7,080,136
Net earnings, As reported	$ 53,388	$ 38,906	$ 46,385	$ 33,961	$ 42,950	$ 27,132	$ 49,998	$ 39,327	$ 172,640	$ 159,407	$ 163,677
Diluted earnings per share, As reported	$ 1.50	$ 1.10	$ 1.32	$ 0.95	$ 1.20	$ 0.76	$ 1.38	$ 1.09	$ 4.87	$ 4.43	$ 4.55
PCM [Member]
Business Acquisition [Line Items]
Net sales, As reported										$ 7,731,190	$ 7,080,136
Net sales, Pro forma										9,207,512	9,241,183
Net earnings, As reported										159,407	163,677
Net earnings, Pro forma										$ 171,102	$ 167,499
Diluted earnings per share, As reported										$ 4.43	$ 4.55
Diluted earnings per share, Pro forma										$ 4.76	$ 4.65