Commitments, Contingent Liabilities and Other Matters (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Future minimum rental payments under operating leases with remaining non-cancelable term
2012	$ 39.6	$ 39.6
2013	30.0	30.0
2014	23.3	23.3
2015	15.1	15.1
2016	12.0	12.0
Thereafter	42.6	42.6
Total minimum payments	162.6	162.6
Total operating lease expense		47.1	48.8	50.0
Future minimum lease payments under capital obligations
2012	6.9	6.9
2013	6.4	6.4
2014	3.7	3.7
2015	3.2	3.2
2016	3.2	3.2
Thereafter	9.8	9.8
Total minimum payments	33.2	33.2
Less: interest	(7.2)	(7.2)
Capital lease obligation	26.0	26.0
Less: current maturities	(4.2)	(4.2)
Long-term portion	21.8	21.8
Contingencies and other matters
Carrying values of accruals	558.3	558.3	436.2
Accruals included in other long-term liabilities	491.8	491.8	368.0
Charge associated with amounts that are deemed uncollectible from an insolvent insurer, portion recorded in other expense, net	18.2
Charge associated with amounts that are deemed uncollectible from an insolvent insurer, portion recorded in discontinued operations, net of tax	1.2
Risk management matters
Contingencies and other matters
Carrying values of accruals	495.6	495.6	366.1
Insurance recovery assets	428.9	428.9	320.0
Insured risk management matters
Contingencies and other matters
Charge resulting from insolvency of insurance carrier for certain risk management matters		19.4
Charge associated with amounts that are deemed uncollectible from an insolvent insurer recorded to other expense, net		18.2
Charge associated with amounts that are deemed uncollectible from an insolvent insurer, portion recorded in discontinued operations, net of tax		$ 1.2