Accounts Recievable, Net (Details) - USD ($)	Dec. 31, 2019	Dec. 31, 2018
Accounts Receivable, Net [Abstract]
Total	$ 11,237,000,000	$ 10,473,000,000
Accounts receivable, net held for sale	(521,000,000)
Accounts receivable, net per Consolidated Balance Sheets	10,716,000,000	10,473,000,000
Pharmaceutical manufacturer receivables related to noninsurance customer contracts	285,000,000	406,000,000
Contractual allowances for certain rebates receivable from manufacturers	343,000,000
Contractual allowances from third-party payors	135,000,000
Allowance for doubtful accounts	300,000,000
Total allowances, Accounts receivable	$ 778,000,000	217,000,000
Express Scripts Holding Company [Member]
Business Acquisition [Line Items]
Allowances for receivables recorded as part of purchase accounting		$ 0