Accounting Policies (Estimated Cash Payments) (Details) $ in Millions	Dec. 31, 2015 USD ($)
Workers' Compensation [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
2015	$ 80.6
2016	54.3
2017	37.0
2018	26.2
2019	19.6
Thereafter	97.8
Total	315.5
Property Damage and Liability Claims [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
2015	30.1
2016	23.8
2017	16.0
2018	8.1
2019	4.0
Thereafter	2.9
Total	84.9
Total [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
2015	110.7
2016	78.1
2017	53.0
2018	34.3
2019	23.6
Thereafter	100.7
Total	$ 400.4