CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (USD $) In Millions	Total	Common stock [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
Balance as of beginning-of-year at Dec. 31, 2010		$ 8,124	$ 3,934	$ 748
Stock compensation/issued for benefit plans		13
Retirement of common stock/cancellation of shares		(345)
Cumulative effect from adoption of new accounting standards			(1,095)	103
Comprehensive income	2,583
Other comprehensive income (loss), net of tax	1,813			1,813
Net income (loss)	770		770
Retirement of common stock			(30)
Dividends declared: Common (2012 - $0.240; 2011 - $0.150)			(48)
Balance as of end-of-period at Sep. 30, 2011	13,987	7,792	3,531	2,664
Balance as of beginning-of-year at Dec. 31, 2011	13,238	7,590	2,969	2,679
Stock compensation/issued for benefit plans		24
Retirement of common stock/cancellation of shares		(400)
Cumulative effect from adoption of new accounting standards			0	0
Comprehensive income	2,442
Other comprehensive income (loss), net of tax	1,471			1,471
Net income (loss)	971		971
Retirement of common stock			0
Dividends declared: Common (2012 - $0.240; 2011 - $0.150)			(67)
Balance as of end-of-period at Sep. 30, 2012	$ 15,237	$ 7,214	$ 3,873	$ 4,150