Quarterly Financial Data (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Quarterly Financial Data [Abstract]
Sales	$ 1,275,000	$ 1,302,343	$ 1,013,959	$ 888,346	$ 1,083,710	$ 1,102,649	$ 844,800	$ 745,909	$ 4,479,648	$ 3,777,068	$ 3,209,782
Gross profit	367,573	388,274	304,914	258,417	317,108	334,785	252,338	216,648	1,319,178	1,120,879	925,297
Net income from continuing operations	135,397	140,826	96,905	80,901	108,680	116,921	80,004	75,464	454,029	381,069	312,310
Net income	$ 135,397	$ 140,826	$ 96,905	$ 80,901	$ 108,680	$ 113,144	$ 80,004	$ 75,464	$ 454,029	$ 377,292	$ 312,310
Diluted net income per share from continuing operations (in dollars per share)	$ 1.98	$ 2.06	$ 1.42	$ 1.19	$ 1.56	$ 1.64	$ 1.13	$ 1.07	$ 6.65	$ 5.40	$ 4.40
Diluted net income per share (in dollars per share)	$ 1.98	$ 2.06	$ 1.42	$ 1.19	$ 1.56	$ 1.59	$ 1.13	$ 1.07	$ 6.65	$ 5.35	$ 4.40