Consolidated Statements of Income (Unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Consolidated Statements of Income (Unaudited) [Abstract]
Revenue	$ 526,182	$ 428,416	$ 1,581,419	$ 1,248,687
Cost of sales	86,768	70,631	258,108	242,453	[1]
Gross profit	439,414	357,785	1,323,311	1,006,234
Operating expenses:
Selling expenses	235,701	184,203	705,599	536,845
General and administrative expenses	121,346	106,369	365,770	311,223
Total operating expenses	357,047	290,572	1,071,369	848,068
Operating income	82,367	67,213	251,942	158,166
Other income (expense), net	1,239	(6,879)	1,505	(7,428)
Income before provision for income taxes	83,606	60,334	253,447	150,738
Provision for income taxes	29,430	13,536	91,035	46,931
Net income	$ 54,176	$ 46,798	$ 162,412	$ 103,807
Net income per share (Note 2):
Basic (in dollars per share)	$ 0.91	$ 0.75	$ 2.65	$ 1.67
Diluted (in dollars per share)	$ 0.87	$ 0.72	$ 2.55	$ 1.61
Weighted-average common shares outstanding (000s):
Basic (in shares)	59,780	62,285	61,265	61,998
Diluted (in shares)	62,060	64,708	63,742	64,408

[1] Includes a $32.8 million charge related to an adverse decision in the Japan customs litigation. See Note 12.