Condensed Consolidated Statements of Cash Flows - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Cash flows from operating activities:
Cash receipts from customers	$ 88,343	$ 84,324
Cash paid for inventory and prescriptions dispensed by retail network pharmacies	(73,748)	(70,851)
Cash paid to other suppliers and employees	(7,000)	(7,019)
Interest received	10	9
Interest paid	(539)	(615)
Income taxes paid	(1,534)	(1,762)
Net cash provided by operating activities	5,532	4,086
Cash flows from investing activities:
Purchases of property and equipment	(888)	(1,102)
Proceeds from sale of property and equipment and other assets	13	11
Acquisitions (net of cash acquired) and other investments	(315)	(168)
Purchase of available-for-sale investments		(39)
Maturity of available-for-sale investments	16	67
Net cash used in investing activities	(1,174)	(1,231)
Cash flows from financing activities:
Increase (decrease) in short-term debt	(774)	745
Proceeds from issuance of long-term debt		3,455
Repayments of long-term debt		(3,579)
Purchase of noncontrolling interest in subsidiary		(39)
Dividends paid	(1,028)	(929)
Proceeds from exercise of stock options	189	193
Payments for taxes related to net share settlement of equity awards	(60)	(71)
Repurchase of common stock	(3,961)	(3,960)
Other	(1)	(4)
Net cash used in financing activities	(5,635)	(4,189)
Effect of exchange rate changes on cash and cash equivalents		2
Net decrease in cash and cash equivalents	(1,277)	(1,332)
Cash and cash equivalents at the beginning of the period	3,371	2,459
Cash and cash equivalents at the end of the period	2,094	1,127
Reconciliation of net income to net cash provided by operating activities:
Net income	2,051	2,071
Adjustments required to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	1,242	1,236
Goodwill impairment	135
Stock-based compensation	108	107
Loss on early extinguishment of debt		542
Deferred income taxes and other noncash items	21	75
Change in operating assets and liabilities, net of effects from acquisitions:
Accounts receivable, net	(114)	(1,279)
Inventories	492	(167)
Other current assets	(31)	(170)
Other assets	(38)	(53)
Accounts payable and claims and discounts payable	180	1,164
Accrued expenses	1,345	555
Other long-term liabilities	141	5
Net cash provided by operating activities	$ 5,532	$ 4,086