Debt (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Notes and other indebtedness
Amount outstanding	$ 1,038.4	$ 1,011.6
Less current portion of debt	564.5	519.4
Long-term debt	473.9	492.2
Accounts receivable securitization program
Notes and other indebtedness
Amount outstanding	135.0	135.0
Secured promissory notes
Notes and other indebtedness
Amount outstanding	13.1	14.5
Equipment credit facilities
Notes and other indebtedness
Amount outstanding		12.0
Real estate credit agreement
Notes and other indebtedness
Amount outstanding	100.8	101.7
Term loan credit facility
Notes and other indebtedness
Amount outstanding	125.0	125.0
Series C convertible senior debentures
Notes and other indebtedness
Amount outstanding		90.1
Revolving credit facilities
Notes and other indebtedness
Amount outstanding	78.6	31.1
Senior notes
Notes and other indebtedness
Amount outstanding	370.0	370.0
Related party credit agreements
Notes and other indebtedness
Amount outstanding	107.4	114.9
Other indebtedness
Notes and other indebtedness
Amount outstanding	16.6	17.3
Carrying Value | Series C convertible senior debentures
Notes and other indebtedness
Amount outstanding	$ 91.9