Goodwill and Other Intangible Assets (Details) - USD ($) $ in Millions	3 Months Ended			6 Months Ended
	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Goodwill and Other Intangible Assets
Goodwill, gross	$ 28.0			$ 28.0		$ 28.0
Goodwill, net	28.0			28.0		28.0
Finite-Lived Intangible Assets, Net
Other intangible assets, accumulated amortization	(5.5)			(5.5)		(5.5)
Intangible Assets, Net (Including Goodwill)
Total goodwill and other intangible assets, gross	50.2			50.2		163.6
Total goodwill and other intangible assets, net	44.7			44.7		158.1
Research and development	74.3		$ 89.7	378.0	$ 162.9
Technology, patents, and trade names
Finite-Lived Intangible Assets, Net
Other intangible assets, gross	6.7			6.7		6.7
Other intangible assets, accumulated amortization	(5.5)			(5.5)		(5.5)
Other intangible assets, net	1.2			1.2		1.2
In-process research and development
Finite-Lived Intangible Assets, Net
Other intangible assets, gross	15.5			15.5		128.9
Other intangible assets, net	$ 15.5			$ 15.5		128.9
Intangible Assets, Net (Including Goodwill)
Carrying value of Trevyent intangible asset						$ 107.3
In Process Research and Development, Trevyent
Intangible Assets, Net (Including Goodwill)
Finite-lived intangible asset impairment		$ 107.3
In Process Research and Development, Biomechanical Lungs
Intangible Assets, Net (Including Goodwill)
Research and development		$ 6.1