Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Cash flows from operating activities:
Cash receipts from customers	$ 66,487	$ 63,751
Cash paid for inventory and prescriptions dispensed by retail network pharmacies	(39,171)	(36,969)
Insurance benefits paid	(15,456)	(14,303)
Cash paid to other suppliers and employees	(8,270)	(8,187)
Interest and investment income received	222	206
Interest paid	(876)	(1,128)
Income taxes paid	(44)	(65)
Net cash provided by operating activities	2,892	3,305
Cash flows from investing activities:
Proceeds from sales and maturities of investments	2,177	1,288
Purchases of investments	(3,131)	(1,535)
Purchases of property and equipment	(829)	(742)
Acquisitions (net of cash acquired)	(84)	(613)
Other	0	5
Net cash used in investing activities	(1,867)	(1,597)
Cash flows from financing activities:
Net borrowings of short-term debt	252	255
Proceeds from issuance of long-term debt	0	3,946
Repayments of long-term debt	(3,049)	(1,008)
Dividends paid	(656)	(652)
Proceeds from exercise of stock options	212	154
Payments for taxes related to net share settlement of equity awards	(3)	(16)
Other	0	(4)
Net cash provided by (used in) financing activities	(3,244)	2,675
Net increase (decrease) in cash, cash equivalents and restricted cash	(2,219)	4,383
Cash, cash equivalents and restricted cash at the beginning of the period	8,130	5,954
Cash, cash equivalents and restricted cash at the end of the period	5,911	10,337
Reconciliation of net income to net cash provided by operating activities:
Net income	2,224	2,012
Adjustments required to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	1,126	1,086
Stock-based compensation	87	96
Deferred income taxes and other noncash items	(166)	(35)
Change in operating assets and liabilities, net of effects from acquisitions:
Accounts receivable, net	(2,093)	(2,715)
Inventories	879	541
Other assets	(223)	(1,119)
Accounts payable and pharmacy claims and discounts payable	576	1,928
Health care costs payable and other insurance liabilities	294	139
Other liabilities	$ 188	$ 1,372