Schedule of Accrued Expenses (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Accrued Expenses [Line Items]
Health insurance	$ 9.5	$ 11.1
Workers' compensation	16.3	14.0
Legal and other settlements	6.9	5.9
Lease liability	1.2	5.0
Charity care	0.6	2.6
Estimated Medicare cap liability	4.8	3.1
Other	15.6	26.8
Accrued expense, Total	$ 54.9	$ 68.5