Balance Sheet Components (Other Assets) (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Schedule of Other Assets [Line Items]
Investments in subsidiaries	$ 0.0	$ 0.0
Other long-term assets	79.6	172.2
Other Assets, Noncurrent	305.6	568.6
Other assets | Agila Specialties
Schedule of Other Assets [Line Items]
Investments in subsidiaries	0.0	75.8
Clean energy investments | Other assets
Schedule of Other Assets [Line Items]
Investments in subsidiaries	$ 226.0	$ 320.6