Debt (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Notes and other indebtedness
Amount outstanding	$ 951.6	$ 1,011.6
Less current portion of debt	444.6	519.4
Long-term debt	507.0	492.2
Accounts receivable securitization program
Notes and other indebtedness
Amount outstanding	150.0	135.0
Secured promissory notes
Notes and other indebtedness
Amount outstanding	7.6	14.5
Equipment credit facilities
Notes and other indebtedness
Amount outstanding		12.0
Real estate credit agreement
Notes and other indebtedness
Amount outstanding	99.8	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	62.4	90.1
Revolving credit facilities
Notes and other indebtedness
Amount outstanding	114.0	31.1
Senior notes
Notes and other indebtedness
Amount outstanding	370.0	370.0
Related party credit agreements
Notes and other indebtedness
Amount outstanding	6.9	114.9
Other indebtedness
Notes and other indebtedness
Amount outstanding	$ 15.9	$ 17.3