Supplemental Cash Flow Information Significant Non-Cash Investing Activities(Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Outstanding receivables from outside parties for the funding of capital expenditures	$ 10.7	$ 23.0	$ 32.1
Purchases of property and equipment accrued in accounts payable	$ 16.4	$ 26.2	$ 51.3