Balance Sheet Components (Other Long-term Obligations) (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Schedule of Other Noncurrent Liabilities [Line Items]
Employee benefit liabilities	$ 428.9	$ 408.2
Contingent consideration	461.4	453.7
Tax contingencies	159.2	237.7
Other	12.4	132.1
Other long-term obligations	1,127.2	1,235.7
Clean energy investments
Schedule of Other Noncurrent Liabilities [Line Items]
Other long-term obligations	264.8	171.8
Other long-term obligations
Schedule of Other Noncurrent Liabilities [Line Items]
Contingent consideration	$ 261.9	$ 285.9