Major Customers, Partnerships and Strategic Alliances (Tables)

6 Months Ended

Jun. 30, 2013

Shire AG [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Revenues recognized under the agreement

Revenues recognized under the agreement with Shire for the three and six months ended June 30, 2013 and June 30, 2012, were as follows (in thousands):

	Three months ended June 30,				Six months ended June 30,
	2013		2012		2013		2012
Revenue related to Shire Collaboration:
Amortization of upfront fee	$	542	$	542	$	1,083	$	903
Research services		4,157		1,517		7,372		2,072
Total	$	4,699	$	2,059	$	8,455	$	2,975

Sigma-Aldrich Corporation [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Revenues recognized under the agreement

Revenues recognized under the agreement with Sigma for the three and six months ended June 30, 2013 and June 30, 2012, were as follows (in thousands):

	Three months ended June 30,				Six months ended June 30,
	2013		2012		2013		2012
Revenue related to Sigma Collaboration:
Royalty revenues	$	196	$	306	$	510	$	607
License fee and milestone revenues		1,250		1,000		1,250		1,000
Total	$	1,446	$	1,306	$	1,760	$	1,607