Consolidated Statements Of Operations (USD $) In Thousands, except Per Share data	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Consolidated Statements Of Operations [Abstract]
Revenues	$ 821,839	$ 553,219	$ 2,329,002	$ 1,566,703
Cost of revenues:
Subscription	471,823	292,406	1,277,018	817,353
Fulfillment expenses	64,794	52,063	187,728	149,212
Total cost of revenues	536,617	344,469	1,464,746	966,565
Gross profit	285,222	208,750	864,256	600,138
Operating expenses:
Technology and development	69,480	42,108	178,250	117,370
Marketing	89,108	81,238	288,350	230,990
General and administrative	29,792	15,903	83,460	46,590
Total operating expenses	188,380	139,249	550,060	394,950
Operating income	96,842	69,501	314,196	205,188
Other income (expense):
Interest expense	(4,915)	(4,945)	(15,083)	(14,797)
Interest and other income	1,696	853	3,574	2,746
Income before income taxes	93,623	65,409	302,687	193,137
Provision for income taxes	31,163	27,442	111,780	79,379
Net income	$ 62,460	$ 37,967	$ 190,907	$ 113,758
Net income per share:
Basic	$ 1.19	$ 0.73	$ 3.63	$ 2.17
Diluted	$ 1.16	$ 0.70	$ 3.53	$ 2.09
Weighted average common shares outstanding:
Basic	52,569	52,142	52,599	52,510
Diluted	53,870	53,931	54,008	54,341