Subsequent Events	6 Months Ended
	Jun. 30, 2020
Subsequent Events [Abstract]
Subsequent Events	Subsequent EventsIn July 2020, the Company entered into a Solar Power Purchase and Energy Services Agreement with Onyx Development Group LLC (Onyx) for the installation and operation of a solar photovoltaic generating system and battery energy storage system at the Company's cell therapy manufacturing facility in Newark, California. The agreement has a term of 20 years and is expected to commence in the first quarter of 2021. The Company is obligated to pay for electricity generated from the system at an agreed rate for the duration of the agreement term. Termination of the agreement by the Company will result in a termination payment due of approximately $4.3 million. In connection with the agreement, the Company will maintain a letter of credit for the benefit of Onyx in the amount of $4.3 million and increased the letter of credit for the benefit of the landlord of the Newark manufacturing facility by $0.9 million.