Other Assets - Other Assets (Details) - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015
Other Assets
Deferred compensation plan	$ 90.8	$ 90.5
Amounts recoverable for capping, closure and post-closure obligations	27.0	25.9
Reinsurance receivable	53.9	44.0
Interest rate swaps	31.7	16.5
Other	82.7	83.7
Total	$ 286.1	$ 260.6