Condensed Consolidated Statements Of Income (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Condensed Consolidated Statements of Income [Abstract]
Revenues	$ 376,920	$ 363,827	$ 689,349	$ 675,483
Cost of sales	174,349	162,960	330,551	308,767
Gross profit	202,571	200,867	358,798	366,716
Selling, general and administrative expenses	153,370	150,246	290,525	278,445
Restructuring charges (Note 6)	4,060		6,310
Asset impairment charges (Note 3)	3,230	202	3,230	202
Income from operations	41,911	50,419	58,733	88,069
Foreign currency transaction losses, net	220	814	2,988	3,414
Interest income	(403)	(517)	(880)	(823)
Interest expense	128	266	319	475
Other (income) expense, net	(30)	195	(171)	167
Income before income taxes	41,996	49,661	56,477	84,836
Income tax expense	18,719	14,305	24,076	20,519
Net income	23,277	35,356	32,401	64,317
Dividends on Series A convertibles preferred shares (Note 13)	3,033		5,166
Dividend equivalents on Series A convertible preferred shares related to redemption value accretion and beneficial conversion feature (Note 13)	721		1,339
Net income attributable to common stockholders	$ 19,523	$ 35,356	$ 25,896	$ 64,317
Net income per common share (Note 12):
Basic	$ 0.19	$ 0.40	$ 0.26	$ 0.73
Diluted	$ 0.19	$ 0.40	$ 0.25	$ 0.72