Schedule I Condensed Statement of Comprehensive Income (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Revenues:
Investment and other income	$ 710	$ 779	$ 745
Total revenues	157,107	130,474	122,489
Operating costs:
Interest expense	790	618	708
Total operating costs	146,086	120,200	112,866
Loss before income taxes	10,231	9,656	8,915
Benefit for income taxes	4,363	4,037	3,242
Net earnings	5,813	5,619	5,625
Other comprehensive loss	(1,942)	(484)	(1,346)
Comprehensive income	3,871	5,135	4,279
Parent Company [Member]
Revenues:
Investment and other income	396	293	252
Total revenues	396	293	252
Operating costs:
Operating costs	(17)	1	(9)
Interest expense	717	554	618
Total operating costs	700	555	609
Loss before income taxes	(304)	(262)	(357)
Benefit for income taxes	111	96	130
Loss of parent company	(193)	(166)	(227)
Equity in undistributed income of subsidiaries	6,006	5,785	5,852
Net earnings	5,813	5,619	5,625
Other comprehensive loss	(1,942)	(484)	(1,346)
Comprehensive income	$ 3,871	$ 5,135	$ 4,279