Condensed Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
Cash flows from operating activities:
Net loss	$ (17,636)	$ (12,655)
Adjustments to reconcile net loss to net cash (used in) provided by operating activities:
Depreciation and amortization	1,938	1,787
Stock-based compensation	5,568	6,046
Change in fair value of contingent consideration related to acquisition	(8,228)	5,200
Research and development license	0	752
Accretion of interest on convertible note	2,453	0
Amortization of deferred financing costs	303	0
Non-cash foreign exchange gain	4,050	0
Changes in operating assets and liabilities:
Accounts receivable and other receivables	(1,343)	(968)
Inventories	(8,512)	93
Prepaid expenses and other current assets	(880)	(622)
Accounts payable	2,208	(1,125)
Accrued payroll	1,576	2,351
Accrued expenses and other liabilities	3,231	637
Other liabilities	0	100
Net cash (used in) provided by operating activities	(15,272)	1,596
Cash flows from investing activities:
Purchases of marketable securities	(107,454)	0
Maturities of marketable securities	64,820	0
Net cash used in investing activities	(9,902)	(1,620)
Net cash used in investing activities	(52,536)	(1,620)
Cash flows from financing activities:
Proceeds from sale of common stock under employee stock purchase plan	1,446	1,646
Proceeds from exercise of stock options	1,596	3,160
Minimum tax withholding paid on behalf of employees for restricted stock units	(2,320)	0
Funding of restricted cash account	0	5,395
Release of restricted cash account	0	(5,395)
Net cash provided by financing activities	722	4,806
Effect of exchange rate changes on cash and cash equivalents	(529)	(414)
Net decrease in cash and cash equivalents	(67,615)	4,368
Cash and cash equivalents, beginning of period	95,152	45,118
Cash and cash equivalents, end of period	27,537	49,486
Supplemental disclosure of cash flow information:
Cash paid for interest	1,047	0
Cash paid for income taxes	239	0
Non-cash investing and financing activities:
Landlord funded leasehold improvements	6,669	0
Fair value of OUS Milestone Shares (note 9)	38,372	0
Acquisition of property and equipment included in accounts payable	$ 2,351	$ 0