Revenue Recognition and Sales Returns Reserves - Additional Information (Detail)	6 Months Ended
	Jun. 30, 2013
Merck-Serono [Member] | Maximum [Member]
Revenue Recognition [Line Items]
Revenue recognition, recorded revenue cost plus percentage	30.00%
Merck-Serono [Member] | Minimum [Member]
Revenue Recognition [Line Items]
Revenue recognition, recorded revenue cost plus percentage	20.00%
Milestone 1 [Member]
Revenue Recognition [Line Items]
Discount volume levels	10,000,000
Milestone 2 [Member]
Revenue Recognition [Line Items]
Discount volume levels	20,000,000
Milestone 3 [Member]
Revenue Recognition [Line Items]
Discount volume levels	30,000,000