Commitments and Contingencies (Details) $ in Millions	1 Months Ended						6 Months Ended	12 Months Ended
	Jul. 31, 2017 USD ($)	Apr. 30, 2017 defendant	Mar. 31, 2017 lawsuit	Sep. 30, 2015 pharmacy	Oct. 31, 2010 plaintiff	Feb. 28, 2006 lawsuit item director	Jun. 30, 2017 item store	Dec. 31, 2016 item
Loss contingencies
Number of store leases guaranteed | store							86
Number of material accruals for outstanding legal matters							0
Number of states in which plaintiffs reside								11
Number of pharmacies indicated in subpoena | pharmacy				8
Number of defendants | lawsuit			4
Number of legal proceedings, government investigations, inquiries and audits expected to be material							0
Omnicare, Inc.
Loss contingencies
New claims filed, number | lawsuit						2
Number of officers named in lawsuit						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
Controlled Substances Act
Loss contingencies
Litigation settlement, amount | $	$ 5
Cherokee Nation Opioid Litigation
Loss contingencies
Number of defendants | defendant		6