License and Collaboration Agreements (Tables)

6 Months Ended

Jun. 30, 2014

Organization Consolidation And Presentation Of Financial Statements [Abstract]

Schedule of Revenue Recognized and Assets and Liabilities under Collaborative Arrangements

During the three and six months ended June 30, 2014 and 2013, the Company recognized revenue based on the following components of the Sanofi agreement:

	Three months ended June 30,				Six months ended June 30,
(in thousands)	2014		2013		2014		2013
Upfront payment	$	13,268	$	1,250	$	14,518	$	2,500
Milestone payments		5,529		521		6,049		1,042
Development services		3,040		14,682		13,740		26,272
Manufacturing services and other		5,978		1,999		6,542		2,740
Total	$	27,815	$	18,452	$	40,849	$	32,554

As of June 30, 2014 and December 31, 2013, the Company maintained the following assets and liabilities related to the Sanofi agreement:

(in thousands)	June 30, 2014		December 31, 2013
Accounts receivable, billed	$	3,390	$	2,357
Accounts receivable, unbilled		2,938		3,417
Deferred revenue		46,283		73,392