Shareholders' Equity (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Shareholders' equity activity [Roll Forward]
Balance at beginning of period			$ 16,298	$ 13,615
Shares repurchased				(500)
Stock plans			254	357
Payments of dividends to shareholders			(306)	(254)
Other			(44)	(26)
Comprehensive income (loss)	$ 157	$ 775	(487)	1,395
Balance at end of period	15,715	14,587	15,715	14,587
Company shareholders' equity
Shareholders' equity activity [Roll Forward]
Balance at beginning of period			16,267	13,581
Shares repurchased				(500)
Stock plans			254	357
Payments of dividends to shareholders			(306)	(254)
Other			(42)	(22)
Comprehensive income (loss)			(488)	1,400
Balance at end of period	15,685	14,562	15,685	14,562
Noncontrolling interest in consolidated subsidiaries
Shareholders' equity activity [Roll Forward]
Balance at beginning of period			31	34
Shares repurchased				0
Stock plans			0	0
Payments of dividends to shareholders			0	0
Other			(2)	(4)
Comprehensive income (loss)			1	(5)
Balance at end of period	$ 30	$ 25	$ 30	$ 25