CONDENSED CONSOLIDATED STATEMENT OF CASH FLOWS (Unaudited) (USD $)	6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011
Cash flows from operating activities:
Net loss	$ (19,551,000)	$ (11,410,000)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	12,741,000	10,786,000
Amortization of intangible assets	9,103,000	4,206,000
Stock-based compensation, net of forfeitures	19,143,000	17,334,000
Loss/(gain) on disposal of property and equipment	(622,000)	11,000
Deferred income taxes	(2,785,000)	0
Tax benefit from stock-based compensation	16,135,000	11,585,000
Excess tax benefits from stock-based compensation	(16,135,000)	(11,607,000)
Changes in operating assets and liabilities:
Accounts receivable, net	1,887,000	185,000
Inventories	(159,000)	1,311,000
Prepaid expenses and other current assets	(29,440,000)	(38,149,000)
Other assets	(211,000)	(887,000)
Accounts payable	2,880,000	(20,786,000)
Accrued and other liabilities	(33,086,000)	(20,787,000)
Deferred revenue	1,478,000	194,000
Net cash used in operating activities	(38,622,000)	(58,014,000)
Cash flows from investing activities:
Acquisition of business and intangibles, net of cash acquired	(24,077,000)	(134,036,000)
Purchases of property and equipment	(17,193,000)	(9,064,000)
Capitalization of software and website development costs	(5,873,000)	(5,044,000)
Proceeds from sale of equipment	682,000	20,000
Net cash used in investing activities	(46,461,000)	(148,124,000)
Cash flows from financing activities:
Principal payments of capital lease obligations	0	(5,000)
Proceeds from issuance of common stock upon exercise of stock options	7,116,000	18,227,000
Excess tax benefits from stock-based compensation	16,135,000	11,607,000
Net cash provided by financing activities	23,251,000	29,829,000
Net decrease in cash and cash equivalents	(61,832,000)	(176,309,000)
Cash and cash equivalents, beginning of period	179,915,000	252,244,000
Cash and cash equivalents, end of period	118,083,000	75,935,000
Supplemental schedule of non-cash investing activities
Net increase in accrued purchases of property and equipment	1,570,000	193,000
Amount due from adjustment of net working capital from acquired business	0	426,000
Remaining amount due for acquisition of intangible assets	$ 4,760,000	$ 0