Summary of Significant Accounting Policies Income Taxes (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Accounting Changes and Error Corrections [Abstract]
Unrecognized Tax Benefits	$ 15.6	$ 15.6	$ 0.0
Interest Related to Uncertain Tax Positions	0.7	0.5
Penalties Related to Uncertain Tax Positions	$ 0.6	$ 2.2