Investments - Held at Cost (Details) - USD ($) $ in Millions	1 Months Ended		12 Months Ended
	Sep. 30, 2015	May 31, 2014	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Cost Method Investments
Payments to acquire investments			$ 36.0	$ 54.2	$ 45.0
Privately-held Companies
Cost Method Investments
Investments held at cost			173.2
Synthetic Genomics Inc
Cost Method Investments
Investments held at cost			$ 100.0
Payments to acquire investments	$ 50.0	$ 50.0