Commitments and Contingencies (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Future minimum annual payments under operating lease agreements [Abstract]
2016	$ 2,024
2017	3,825
2018	3,907
2019	3,901
2020	3,987
Thereafter	22,567
Total	40,211
Rental expense	1,864	$ 1,864	$ 3,548
Adjustments to rental expense	49	3	164
Additional facility charges	2,456	2,117	2,330
Licensing, Service, Supply and Related Party Agreements [Abstract]
License fees and supply costs	388	498	567
Consulting Agreements [Abstract]
Expenses with regard to consulting agreements with scientific specialists	54	67	39
Fair value of options vested included in consulting expenses	6	17	7
MTS-Related Party Agreement
Consulting agreement monthly retainer amount			55
Success fee			300
Proceeds from former licensee	0	$ 7,250	$ 0
Compensatory Damages in a trial	1,660
Seattle Genetics, Inc. [Member]
Licensing, Service, Supply and Related Party Agreements [Abstract]
Commitments, paid from inception	4,601
Future Commitments	$ 13,800
Terms	Milestone and periodic maintenance payments to use ADC technology to link chemotherapeutic agents to monoclonal antibodies that target prostate specific membrane antigen. ADC technology is based in part on technology licensed by SGI from third parties.
Amgen Fremont, Inc. (formerly Abgenix) [Member]
Licensing, Service, Supply and Related Party Agreements [Abstract]
Commitments, paid from inception	$ 1,350
Future Commitments	$ 5,750
Terms	Milestones and royalties to use XenoMouse® technology for generating fully human antibodies to PSMA LLC’s PSMA antigen.
Former Member of PSMA LLC [Member]
Licensing, Service, Supply and Related Party Agreements [Abstract]
Commitments, paid from inception	$ 353
Future Commitments	$ 52,188
Terms	Annual minimum royalty payments and milestones to use technology related to PSMA.
University of Zurich and the Paul Scherrer Institute [Member]
Licensing, Service, Supply and Related Party Agreements [Abstract]
Commitments, paid from inception	$ 270
Future Commitments	$ 1,070
Terms	Annual maintenance and license fee payments, milestones and royalties in respect of licensed technology related to 1404.
Johns Hopkins University Technology [Member]
Licensing, Service, Supply and Related Party Agreements [Abstract]
Commitments, paid from inception	$ 150
Future Commitments	$ 2,760
Terms	Annual minimum royalty payments and milestones to use technology related to PyL.
University of Western Ontario [Member]
Licensing, Service, Supply and Related Party Agreements [Abstract]
Commitments, paid from inception	$ 27
Future Commitments	$ 274
Terms	Annual minimum royalty, administration and milestone payments in respect of licensed technology related to AZEDRA.
Pending termination [Member]
Licensing, Service, Supply and Related Party Agreements [Abstract]
Commitments, paid from inception	$ 251
Future Commitments	$ 14,375
Terms	Payments for programs to be out-licensed or terminated