Commitments and Contingencies (Details) $ in Millions	1 Months Ended						3 Months Ended	12 Months Ended
	Mar. 31, 2017 lawsuit store	Oct. 31, 2016 USD ($)	Sep. 30, 2015 pharmacy	Jun. 30, 2014 USD ($)	Oct. 31, 2010 USD ($) plaintiff	Feb. 28, 2006 lawsuit item director	Mar. 31, 2017 item store	Dec. 31, 2016 USD ($) item
Loss contingencies
Number of store leases guaranteed | store	86						86
Number of material accruals for outstanding legal matters | item							0
Number of states in which plaintiffs reside | item								11
Number of pharmacies indicated in subpoena | pharmacy			8
Number of Caremark entities named as defendants | lawsuit	4
Number of legal proceedings, government investigations, inquiries and audits expected to be material | item							0
Omnicare, Inc.
Loss contingencies
New claims filed, number | lawsuit						2
Number of officers named in lawsuit | item						3
Number of directors named in lawsuit | director						2
Banigan and Templin v. Organon USA, Inc., Omnicare, Inc. and PharMerica Corporation | Omnicare, Inc.
Loss contingencies
Number of former employees | plaintiff					2
Litigation settlement, amount | $					$ 23.0
Omnicare's Nationwide Billing Practices, Pure Service Pharmacy | Omnicare, Inc.
Loss contingencies
Litigation settlement, amount | $								$ 1.5
Auto Label Verification | Omnicare, Inc.
Loss contingencies
Litigation settlement, amount | $				$ 8.0
Controlled Substances Act
Loss contingencies
Litigation settlement, amount | $		$ 5.0