Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Operating activities:
Net loss for basic EPS	$ (20,932)	$ (21,055)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation	2,507	1,586
Depreciation and amortization	406	479
Amortization of debt issuance costs and non-cash interest	161	133
Change in fair value of warrant liabilities	(8,269)	4,258
Change in fair value of embedded derivatives	14	81
Changes in operating assets and liabilities:
Trade accounts receivable	(5,015)	(112)
Inventory, net	(4,918)	223
Prepaid expenses and other current assets	882	(1,027)
Other assets	(534)	421
Accounts payable and accrued expenses	6,911	(61)
Deferred revenue	5,963	0
Net cash used in operating activities	(22,824)	(15,074)
Investing activities:
Purchases of property and equipment	(15)	(830)
Net cash used in investing activities	(15)	(830)
Financing activities:
Proceeds from exercise of common stock options	1,502	0
Net cash provided by financing activities	1,502	0
Net (decrease) increase in cash and cash equivalents	(21,337)	(15,904)
Cash and cash equivalents at beginning of period	72,021	41,228
Cash and cash equivalents at end of period	50,684	25,324
Noncash investing and financing activities:
Change in purchases of property and equipment in accounts payable	$ (310)	$ 0