Consolidated Statements Of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Consolidated Statements Of Operations [Abstract]
Revenues	$ 3,204,577	$ 2,162,625	$ 1,670,269
Cost of revenues:
Subscription	1,789,596	1,154,109	909,461
Fulfillment expenses	250,305	203,246	169,810
Total cost of revenues	2,039,901	1,357,355	1,079,271
Gross profit	1,164,676	805,270	590,998
Operating expenses:
Marketing	402,638	293,839	237,744
Technology and development	259,033	163,329	114,542
General and administrative	117,937	64,461	46,773
Legal Settlement	9,000
Total operating expenses	788,608	521,629	399,059
Operating income	376,068	283,641	191,939
Other income (expense):
Interest expense	(20,025)	(19,629)	(6,475)
Interest and other income	3,479	3,684	6,728
Income before income taxes	359,522	267,696	192,192
Provision for income taxes	133,396	106,843	76,332
Net income	$ 226,126	$ 160,853	$ 115,860
Net income per share:
Basic	$ 4.28	$ 3.06	$ 2.05
Diluted	$ 4.16	$ 2.96	$ 1.98
Weighted-average common shares outstanding:
Basic	52,847	52,529	56,560
Diluted	54,369	54,304	58,416