Debt - Maturities (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Annual maturities of debt:
2016	$ 0.7
2017	20.1
2018	0.2
2019	15.2
2020	25.1
Thereafter	205.4
Total debt	266.7	$ 355.0
Interest expense	$ 13.0	$ 13.3	$ 13.4