Condensed Consolidated Statements of Cash Flows (USD $) In Millions, unless otherwise specified	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
Cash flows from operating activities:
Cash receipts from customers	$ 85,408	$ 84,463
Cash paid for inventory and prescriptions dispensed by retail network pharmacies	(67,826)	(67,464)
Cash paid to other suppliers and employees	(10,760)	(10,120)
Interest received	5	2
Interest paid	(369)	(411)
Income taxes paid	(2,213)	(1,530)
Net cash provided by operating activities	4,245	4,940
Cash flows from investing activities:
Purchases of property and equipment	(1,330)	(1,314)
Proceeds from sale-leaseback transactions	156	427
Proceeds from sale of property and equipment	13	0
Acquisitions (net of cash acquired) and other investments	(354)	(303)
Proceeds from sale of subsidiary	(107)	0
Proceeds from sale of subsidiary	0	7
Net cash used in investing activities	(1,622)	(1,183)
Cash flows from financing activities:
Increase in short-term debt	124	75
Repayments of long-term debt	0	(56)
Purchase of noncontrolling interest in subsidiary	0	(26)
Dividends paid	(829)	(627)
Proceeds from exercise of stock options	431	677
Excess tax benefits from stock-based compensation	48	21
Repurchase of common stock	(2,272)	(4,001)
Net cash used in financing activities	(2,498)	(3,937)
Effect of exchange rate changes on cash and cash equivalents	5	0
Net increase (decrease) in cash and cash equivalents	130	(180)
Cash and cash equivalents at beginning of period	1,375	1,413
Cash and cash equivalents at end of period	1,505	1,233
Reconciliation of net income to net cash provided by operating activities:
Net income	3,331	2,746
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	1,412	1,297
Stock-based compensation	101	97
Deferred income taxes and other noncash items	129	87
Change in operating assets and liabilities, net of effects from acquisitions:
Accounts receivable, net	(1,518)	(296)
Inventories	(39)	(586)
Other current assets	(176)	(425)
Other assets	(125)	(142)
Accounts payable and claims and discounts payable	697	919
Accrued expenses	32	325
Other long-term liabilities	49	68
Net cash provided by operating activities	4,245	4,940
Goodwill	$ 26,550