Income Taxes - Summary of Unrecognized Tax Benefits (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance as of January 1	$ (5.8)	$ (4.4)	$ (5.4)
Increases related to prior years' tax positions	0.0	(2.8)	(1.0)
Increases related to current year tax positions	(0.5)	(0.4)	(0.3)
Decreases related to prior year's tax positions	0.1	0.0	0.9
Settlements with taxing authorities	0.3	0.7	0.5
Expiration of the statute of limitations	0.7	1.1	0.9
Balance at December 31	(5.2)	$ (5.8)	$ (4.4)
Unrecognized tax benefits that would impact of effective tax rate	$ 3.9