QUARTERLY FINANCIAL DATA (Unaudited) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2011		Dec. 31, 2010		Dec. 31, 2009
QUARTERLY FINANCIAL DATA (Unaudited)
Net Sales	$ 409,957	$ 474,709	$ 462,145	$ 356,419	$ 318,665	$ 381,466	$ 365,701	$ 238,110	$ 1,703,230		$ 1,303,942		$ 1,143,299
Gross Profit	214,244	250,307	244,221	185,537	164,410	197,926	193,350	124,554	894,309		680,240		612,316
Net income	$ 64,536	$ 82,392	$ 84,248	$ 55,043	$ 49,132	$ 66,496	$ 63,838	$ 32,563	$ 286,219		$ 212,029		$ 208,716
Net Income per Common Share
Basic (in dollars per share)	$ 0.37	$ 0.47	$ 0.48	$ 0.31	$ 0.28	$ 0.38	$ 0.36	$ 0.18	$ 1.62	[1]	$ 1.20	[1]	$ 1.16	[1]
Diluted (in dollars per share)	$ 0.35	$ 0.44	$ 0.45	$ 0.29	$ 0.26	$ 0.36	$ 0.34	$ 0.18	$ 1.53	[1]	$ 1.14	[1]	$ 1.10	[1]

[1] Stock Split - On January 11, 2012, the Company announced that its Board of Directors had approved a two-for-one stock split of its common stock to be effected in the form of a 100% stock dividend. The stock dividend was issued on February 15, 2012. See Note 1 for additional information.