Quarterly Financial Data (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Quarterly Financial Data [Abstract]
Sales	$ 1,627,120	$ 1,651,415	$ 1,502,532	$ 1,297,473	$ 1,431,049	$ 1,478,726	$ 1,364,920	$ 1,153,782	$ 6,078,540	$ 5,428,477	$ 4,516,629
Gross profit	$ 391,273	401,270	385,176	323,481	367,812	363,962	350,386	242,491	1,501,200	1,324,651	1,105,623
Net income		$ 95,529	$ 92,540	$ 55,714	$ 31,474	$ 81,888	$ 62,041	$ (2,911)	$ 335,257	$ 172,492	$ 212,948
Diluted net income per share (in dollars per share)	$ 1.47	$ 1.50	$ 1.43	$ 0.85	$ 0.49	$ 1.28	$ 0.97	$ (0.05)	$ 5.24	$ 2.69	$ 3.27