Acquisitions Proforma (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Loss on early extinguishment of debt included in pro forma income	$ 0	$ 521	$ 0	$ 521
Omnicare, Inc. [Member]
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Total revenues	39,374	36,390	115,652	106,391
Income from continuing operations	$ 1,318	$ 929	$ 3,774	$ 3,261
Basic earnings per share from continuing operations	$ 1.18	$ 0.80	$ 3.35	$ 2.78
Diluted earnings per share from continuing operations	$ 1.17	$ 0.79	$ 3.32	$ 2.76
Severance costs, accelerated stock-based compensation and transaction costs excluded from pro forma income	$ 113		$ 129

The pro forma income from continuing operations before changes in accounting and extraordinary items, net of tax effect per basic share of common stock for a period as if the business combination or combinations had been completed at the beginning of a period.

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The pro forma income from continuing operations before changes in accounting and extraordinary items, net of tax effect, per diluted share of common stock for a period as if the business combination or combinations had been completed at the beginning of a period.

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The pro forma income from continuing operations before changes in accounting and extraordinary items, net of tax effect, for the period as if the business combination or combinations had been completed at the beginning of a period.

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Difference between the fair value of payments made and the carrying amount of debt which is extinguished prior to maturity.

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