Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Consolidated Statements of Income [Abstract]
Revenue	$ 2,207,797	$ 2,247,047	$ 2,569,495
Cost of sales	500,457	489,510	478,434
Gross profit	1,707,340	1,757,537	2,091,061
Operating expenses:
Selling expenses	922,083	951,372	1,116,572
General and administrative expenses	554,153	561,463	622,301
Total operating expenses	1,476,236	1,512,835	1,738,873
Operating income	231,104	244,702	352,188
Other income (expense), net (Note 22)	(18,265)	(32,743)	(53,681)
Income before provision for income taxes	212,839	211,959	298,507
Provision for income taxes	69,753	78,913	109,331
Net income	$ 143,086	$ 133,046	$ 189,176
Net income per share:
Basic (in dollars per share)	$ 2.58	$ 2.29	$ 3.20
Diluted (in dollars per share)	$ 2.55	$ 2.25	$ 3.11
Weighted-average common shares outstanding:
Basic (in shares)	55,412	57,997	59,073
Diluted (in shares)	56,097	59,057	60,887