Income Tax Unrecognized Tax Benefit (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Presented net against non-current deferred tax assets	$ 37.9	$ 32.7	$ 30.9
Unrecognized Tax Benefits, Decrease Resulting from Current Period Tax Positions	37.9	32.7
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at beginning of year	39.7	39.5	59.8
Additions for tax positions related to the current year	13.5	1.7	1.8
Additions for tax positions of prior years	13.6	0.0	2.2
Reductions for tax positions of prior years	0.0	0.0	(5.5)
Settlements	(12.8)	0.0	(0.9)
Release due to statute expiration and legislative changes	(14.6)	(2.3)	(9.6)
Foreign currency adjustment	2.5	0.8	(8.3)
Balance at end of year	$ 41.9	$ 39.7	$ 39.5