Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Net earnings	$ 261	$ 426	$ 332	$ 394	$ 413	$ 1,639	$ 439	$ 468	$ 1,413	$ 2,959	$ 1,879
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Total other comprehensive income (loss), net of tax									(35)	(190)	24
Other comprehensive income (loss), before reclassifications, net of tax									(71)	(183)	158
Reclassifications from accumulated other comprehensive income (loss) to net earnings									36	(7)	(134)
Total comprehensive income (loss)									1,378	2,769	1,903
Continuing Operations [Member]
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Cumulative translation adjustment									(5)	(9)	(2)
Net actuarial gain (loss) and prior service cost									(30)	(163)	207
Unrealized gain (loss) on securities									0	(3)	1
Total other comprehensive income (loss), net of tax									(35)	(175)	206
Discontinued Operations [Member]
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Total other comprehensive income (loss), net of tax									0	(15)	(182)
Other comprehensive income (loss), before reclassifications, net of tax									0	15	(4)
Reclassifications from accumulated other comprehensive income (loss) to net earnings									$ 0	$ (30)	$ (178)