Commitments and Contingencies (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Future minimum payments under operating leases
2013	$ 14,300,000
2014	11,700,000
2015	10,500,000
2016	9,400,000
2017	7,200,000
2018	6,700,000
2019 and beyond	11,400,000
Future minimum rentals to be received under operating subleases
2013	600,000
2014	500,000
2015	300,000
2016 and beyond	0
Rent expense	19,500,000	19,300,000	19,800,000
Specialty Pharmaceutical Management
Insurance
Period for which insurance policies have been renewed	1 year
General liability
Insurance
Period for which insurance policies have been renewed	1 year
Insurance coverage per claim for un-aggregated self-insured retention	50,000
General liability | Specialty Pharmaceutical Management
Insurance
Insurance coverage per claim for un-aggregated self-insured retention	250,000
Professional liability
Insurance
Period for which insurance policies have been renewed	1 year
Insurance coverage per claim for un-aggregated self-insured retention	50,000
Professional liability | Specialty Pharmaceutical Management
Insurance
Insurance coverage per claim for un-aggregated self-insured retention	50,000
Professional liability | Behavioral health direct care facilities
Insurance
Period for which insurance policies have been renewed	5 years
Insurance coverage per claim for un-aggregated self-insured retention	500,000
Managed care liability
Insurance
Period for which insurance policies have been renewed	1 year
Insurance coverage per claim for un-aggregated self-insured retention	1,000,000
Insurance coverage per class action claim for un-aggregated self-insured retention	$ 10,000,000