Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013
Operating activities
Net loss	$ (56,675)	$ (37,836)
Adjustments to reconcile net loss to net cash used in operating activities:
Share-based compensation expense	13,185	4,396
Depreciation and amortization	616	817
Noncash interest expense	363	187
Change in value of warrant liability	886	(32)
Other	409	161
Changes in operating assets and liabilities:
Accounts receivable	(380)	(790)
Inventory	22	(1,741)
Prepaid expenses and other current assets	73	5,175
Other assets	(366)	(645)
Accounts payable	1,346	112
Accrued expenses	2,448	(374)
Deferred revenue	(338)
Other liabilities	2	(26)
Total adjustments	18,266	7,240
Net cash used in operating activities	(38,409)	(30,596)
Investing activities
Purchases of property and equipment	(58)	(1,355)
Proceeds from sales of property and equipment		52
Net cash used in investing activities	(58)	(1,303)
Financing activities
Issuance of long-term debt, net	(73)	9,730
Other	(49)	(279)
Net cash provided by (used in) financing activities	(122)	9,451
Effect of exchange rate changes on cash and cash equivalents	134	580
Net decrease in cash and cash equivalents	(38,455)	(21,868)
Cash and cash equivalents at beginning of period	71,639	50,436
Cash and cash equivalents at end of period	33,184	28,568
Supplemental disclosure of cash flow information
Cash paid during the period for interest	911	302
Cash paid for taxes
Supplemental disclosure of noncash financing and investing activities
Issuance of common stock upon exercise of common stock purchase warrants	$ 1,877