Consolidated Statements Of Cash Flows (USD $) In Thousands	6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010
Operating activities
Net loss	$ (38,161)	$ (49,305)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation	2,183	839
Depreciation and amortization	791	676
Amortization of debt issuance costs and non-cash interest	782	805
Change in fair value of preferred stock warrant liability	0	13,020
Changes in operating assets and liabilities:
Trade accounts receivable	1,256	(2,022)
Inventory, net	(263)	(2,244)
Prepaid expenses and other current assets	(104)	141
Other assets	58	(4,466)
Accounts payable and accrued expenses	(901)	3,698
Deferred rent	(30)	(13)
Deferred revenue	(6,118)	3,050
Net cash used in operating activities	(40,507)	(35,821)
Investing activities:
Purchases of property and equipment	(366)	(1,162)
Net cash used in investing activities	(366)	(1,162)
Financing activities:
Proceeds from revolving credit facility	4,242	0
Payments on borrowings of debt and revolving credit facility	(4,883)	(3,435)
Proceeds from exercise of common stock options	14	0
Net cash used in financing activities	(627)	(3,435)
Net decrease in cash and cash equivalents	(41,500)	(40,418)
Cash and cash equivalents at beginning of period	49,172	44,911
Cash and cash equivalents at end of period	$ 7,672	$ 4,493