Consolidated Condensed Statements of Comprehensive Income (Parenthetical) (Unaudited) (USD $) In Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Other comprehensive income (loss):
Tax benefit of change in postretirement benefit plans	$ 13	$ 8	$ 24	$ 18
Tax expense of net change in unrealized gains on investment securities	3	(1)	6	1
Net change in postretirement benefit plans, net of tax:
Tax benefit of amortization of prior service costs	1	1	1	1
Tax benefit of amortization of net actuarial loss	13	8	24	18
Net change in unrealized gains on investment securities, net of tax:
Tax expense of unrealized holding (losses) gains arising during period	0	1	0	(1)
Tax expense of gains realized during the period	$ 3	$ 0	$ 6	$ 0