Balance Sheet Components (Other Long-term Obligations) (Details) - USD ($) $ in Millions	Jun. 30, 2018	Dec. 31, 2017
Schedule of Other Noncurrent Liabilities [Line Items]
Employee benefit liabilities	$ 408.1	$ 408.2
Contingent consideration	433.0	453.7
Tax contingencies	164.0	237.7
Other	48.1	132.1
Other long-term obligations	1,055.2	1,235.7
Clean energy investments
Schedule of Other Noncurrent Liabilities [Line Items]
Other long-term obligations	200.0	171.8
Other long-term obligations
Schedule of Other Noncurrent Liabilities [Line Items]
Contingent consideration	$ 235.0	$ 285.9