Significant Accounting Policies Other Assets (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Property and Equipment, Net	$ 33.5	$ 30.2
Accumulated Depreciation	70.1	61.4
Depreciation expense	8.7	8.2	$ 6.3
Goodwill	$ 9.9	$ 9.9