Recently Issued Accounting Standards (Details) - USD ($) $ in Millions		3 Months Ended	12 Months Ended
	Jan. 01, 2019	Sep. 30, 2019	Dec. 31, 2019	Dec. 31, 2017
Leases
Decrease to retained earnings			$ (5.1)	$ (5.1)
Right-of-use assets	$ 8.2		$ 4.8
Other non-current assets	us-gaap:OtherAssetsNoncurrent		us-gaap:OtherAssetsNoncurrent
Current lease liabilities	$ 4.1		$ 1.8
Other current liabilities	us-gaap:OtherLiabilitiesCurrent		us-gaap:OtherLiabilitiesCurrent
Non-current lease liabilities	$ 4.1		$ 3.0
Other non-current liabilities	us-gaap:OtherLiabilitiesNoncurrent		us-gaap:OtherLiabilitiesNoncurrent
Total operating lease liabilities	$ 8.2		$ 4.8
Operating Lease, Liability, Statement of Financial Position [Extensible List]	us-gaap:OperatingLeaseLiabilityCurrent us-gaap:OperatingLeaseLiabilityNoncurrent		us-gaap:OperatingLeaseLiabilityCurrent us-gaap:OperatingLeaseLiabilityNoncurrent
Reclassification from Property, plant and equipment to other noncurrent assets			$ 23.7
Broader collaboration arrangement
Leases
Reclassification from Property, plant and equipment to other noncurrent assets		$ 23.7
ASU 2016-02
Leases
Decrease to retained earnings	$ (5.1)
Weighted-average remaining lease term	3 years
Weighted-average discount rate	4.90%