Certain Balance Sheet Items - Accounts receivable (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Accounts Receivable, Net, Current [Abstract]
Accounts receivable from product sales to collaborators	$ 16,575	$ 4,996
Accounts receivable from other product sales	2,467	2,442
Accounts receivable from revenues under collaborative agreements	5,001	25,939
Accounts receivable, gross	24,043	33,377
Allowance for distribution fees and discounts	(816)	(967)
Total accounts receivable, net	$ 23,227	$ 32,410