Consolidated Statement of Comprehensive Income (Unaudited) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Statement of Comprehensive Income [Abstract]
Net earnings, including noncontrolling interests	$ 208	$ 145	$ 349	$ 300
Net unrealized gains (losses) on securities:
Unrealized holding gains (losses) on securities arising during the period	(148)	115	(427)	240
Reclassification adjustment for realized gains included in net earnings	(3)	(5)	(1)	(5)
Total net unrealized gains (losses) on securities	(151)	110	(428)	235
Net unrealized gains (losses) on cash flow hedges	(3)	2	(14)	1
Foreign currency translation adjustments	(4)	4	(3)	4
Other comprehensive income (loss), net of tax	(158)	116	(445)	240
Total comprehensive income (loss), net of tax	50	261	(96)	540
Less: Comprehensive income (loss) attributable to noncontrolling interests	(2)	0	(6)	2
Comprehensive income (loss) attributable to shareholders	$ 52	$ 261	$ (90)	$ 538