Consolidated Statements of Income (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Consolidated Statements of Income (Unaudited) [Abstract]
Revenue	$ 612,366	$ 623,500	$ 1,130,394	$ 1,247,123
Cost of sales	154,110	154,028	279,903	300,692
Gross profit	458,256	469,472	850,491	946,431
Operating expenses:
Selling expenses	248,628	245,828	454,670	495,536
General and administrative expenses	151,554	149,442	301,182	308,040
Total operating expenses	400,182	395,270	755,852	803,576
Operating income	58,074	74,202	94,639	142,855
Other income (expense), net	1,581	(3,326)	(4,593)	(6,174)
Income before provision for income taxes	59,655	70,876	90,046	136,681
Provision for income taxes	17,804	24,527	28,465	47,330
Net income	$ 41,851	$ 46,349	$ 61,581	$ 89,351
Net income per share (Note 6):
Basic (in dollars per share)	$ 0.81	$ 0.83	$ 1.15	$ 1.61
Diluted (in dollars per share)	$ 0.81	$ 0.83	$ 1.15	$ 1.59
Weighted-average common shares outstanding:
Basic (in shares)	51,872	55,536	53,466	55,486
Diluted (in shares)	51,925	55,943	53,502	56,030

The aggregate costs related to goods produced and sold and services rendered by an entity during the reporting period. This excludes costs incurred during the reporting period related to financial services rendered and other revenue generating activities.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 924
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 11.L)
-URI http://asc.fasb.org/extlink&oid=6472922&loc=d3e499488-122856

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.2(a),(d))
-URI http://asc.fasb.org/extlink&oid=120395209&loc=SL114868664-224227