Condensed Consolidated Statements of Cash Flows - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Cash flows from operating activities:
Cash receipts from customers	$ 133,055	$ 128,545
Cash paid for inventory and prescriptions dispensed by retail network pharmacies	(110,788)	(106,371)
Cash paid to other suppliers and employees	(11,230)	(11,020)
Interest received	15	14
Interest paid	(869)	(954)
Income taxes paid	(2,040)	(2,194)
Net cash provided by operating activities	8,143	8,020
Cash flows from investing activities:
Purchases of property and equipment	(1,412)	(1,607)
Proceeds from sale-leaseback transactions	265	230
Proceeds from sale of property and equipment and other assets	20	22
Acquisitions (net of cash acquired) and other investments	(502)	(333)
Purchase of available-for-sale investments		(40)
Maturity of available-for-sale investments	21	76
Net cash used in investing activities	(1,608)	(1,652)
Cash flows from financing activities:
Increase (decrease) in short-term debt	(1,764)	340
Proceeds from issuance of long-term debt		3,455
Repayments of long-term debt		(5,185)
Purchase of noncontrolling interest in subsidiary		(39)
Payment of contingent consideration		(26)
Dividends paid	(1,539)	(1,384)
Proceeds from exercise of stock options	314	277
Payments for taxes related to net share settlement of equity awards	(70)	(72)
Repurchase of common stock	(4,361)	(4,000)
Other	(1)	(6)
Net cash used in financing activities	(7,421)	(6,640)
Effect of exchange rate changes on cash and cash equivalents		2
Net decrease in cash and cash equivalents	(886)	(270)
Cash and cash equivalents at the beginning of the period	3,371	2,459
Cash and cash equivalents at the end of the period	2,485	2,189
Reconciliation of net income to net cash provided by operating activities:
Net income	3,336	3,612
Adjustments required to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	1,857	1,847
Goodwill impairment	135
Loss on settlement of defined benefit pension plans	187
Stock-based compensation	173	166
Loss on early extinguishment of debt		643
Deferred income taxes and other noncash items	271	119
Change in operating assets and liabilities, net of effects from acquisitions:
Accounts receivable, net	(280)	(1,714)
Inventories	620	(337)
Other current assets	(212)	2
Other assets	(15)	(86)
Accounts payable and claims and discounts payable	330	1,570
Accrued expenses	1,670	2,149
Other long-term liabilities	71	49
Net cash provided by operating activities	$ 8,143	$ 8,020