Collaborative Arrangements - CRISPR Therapeutics AG (Details) - CRISPR Therapeutics		1 Months Ended	3 Months Ended
	Oct. 26, 2015 USD ($) target	Oct. 31, 2016 USD ($)	Jun. 30, 2016 USD ($)	Dec. 31, 2015 USD ($)
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaborative funding	$ 75,000,000			$ 75,000,000.0
Investment in collaborative partner, pursuant to convertible loan agreement	$ 30,000,000	$ 10,000,000	$ 3,100,000
Right to license, number of targets (up to) | target	6
Collaborative arrangement development and regulatory potential milestone payments maximum	$ 420,000,000
Prior to marketing approval, time period of notice required to terminate (in days)	90 days
Subsequent to marketing approval, time period of notice required to terminate (in days)	270 days