Commitments and Contingencies (Details) (USD $)	1 Months Ended	3 Months Ended	13 Months Ended
	Oct. 31, 2003 pharmacy competitor entity	Mar. 31, 2012 state platform store	Feb. 28, 2012 subpoena
Commitments and Contingencies
Number of store leases guaranteed		76
Number of adjudication platforms under investigation		2
Loss contingencies
Number of additional subpoenas received			2
Number of pharmacies filing putative action	2
Number of competitors against whom putative actions are filed	2
Number of Caremark entities named as defendants	2
Number of states participating in multi-state investigation		28
Lauriello Lawsuit
Loss contingencies
Lauriello lawsuit, amount sought in compensatory damages plus other non-specified damages		3,200,000,000
Multi-state investigation under FTC
Loss contingencies
Amount required to be paid in consumer redress, to be distributed to impacted RxAmerica Medicare Part D beneficiaries		5,000,000