Consolidated Statement of Changes in Shareholders' Equity (Unaudited) - USD ($) shares in Millions, $ in Millions	Total
Balance, beginning of year at Dec. 31, 2013	$ 21,500
Common stock
Employee share-based compensation	94
Compensation amortization under share-based plans and other changes	100
Balance, end of period at Jun. 30, 2014	21,694
Balance, beginning of year at Dec. 31, 2013	24,291
Retained earnings
Net income	1,735
Dividends	(367)
Other	3
Balance, end of period at Jun. 30, 2014	25,662
Balance, beginning of year at Dec. 31, 2013	810
Accumulated other comprehensive income, net of tax
Other comprehensive income (loss)	752
Balance, end of period at Jun. 30, 2014	1,562
Balance, beginning of year at Dec. 31, 2013	(21,805)
Treasury stock (at cost)
Treasury stock acquired - share repurchase authorization	(1,525)
Net shares acquired related to employee share-based compensation plans	(56)
Balance, end of period at Jun. 30, 2014	$ (23,386)
Balance, beginning of year at Dec. 31, 2013	353.5
Common shares outstanding
Treasury stock acquired - share repurchase authorization	(17.3)
Net shares issued under employee share-based compensation plans	2.8
Balance, end of period at Jun. 30, 2014	339.0
Treasury stock (at cost)
Total shareholders' equity	$ 25,532
Total shareholders' equity	24,836
Balance, beginning of year at Dec. 31, 2014	21,843
Common stock
Employee share-based compensation	87
Compensation amortization under share-based plans and other changes	109
Balance, end of period at Jun. 30, 2015	22,039
Balance, beginning of year at Dec. 31, 2014	27,251
Retained earnings
Net income	1,645
Dividends	(372)
Balance, end of period at Jun. 30, 2015	28,524
Balance, beginning of year at Dec. 31, 2014	880
Accumulated other comprehensive income, net of tax
Other comprehensive income (loss)	(711)
Balance, end of period at Jun. 30, 2015	169
Balance, beginning of year at Dec. 31, 2014	(25,138)
Treasury stock (at cost)
Treasury stock acquired - share repurchase authorization	(1,400)
Net shares acquired related to employee share-based compensation plans	(73)
Balance, end of period at Jun. 30, 2015	$ (26,611)
Balance, beginning of year at Dec. 31, 2014	322.2
Common shares outstanding
Treasury stock acquired - share repurchase authorization	(13.5)
Net shares issued under employee share-based compensation plans	2.5
Balance, end of period at Jun. 30, 2015	311.2
Treasury stock (at cost)
Total shareholders' equity	$ 24,121