Balance Sheet Components (Other noncurrent liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Schedule of Other Noncurrent Liabilities [Line Items]
Defined Benefit Pension Plan, Liabilities, Noncurrent	$ 408.2	$ 396.7
Other long-term obligations	1,235.7	1,358.6
Business Combination, Contingent Consideration, Liability	453.7	564.6	$ 526.4
Liability for Uncertainty in Income Taxes, Noncurrent	237.7	239.3
Liabilities, Other than Long-term Debt, Noncurrent	132.1	112.6
Other Noncurrent Liabilities
Schedule of Other Noncurrent Liabilities [Line Items]
Business Combination, Contingent Consideration, Liability	285.9	307.7	$ 491.4	[1]
Clean energy investments
Schedule of Other Noncurrent Liabilities [Line Items]
Other long-term obligations	$ 171.8	$ 302.3

[1] Included in other long-term obligations on the Consolidated Balance Sheets.