Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ 1,760	$ 1,410	$ 2,949	$ 2,782
Other comprehensive income, net of tax
Net unrealized appreciation on securities and derivatives	709	343	281	785
Net translation gains (losses) on foreign currencies	70	(42)	(105)	(68)
Postretirement benefits liability adjustment	(42)	14	(29)	25
Other comprehensive income, net of tax	737	315	147	742
Total comprehensive income	2,497	1,725	3,096	3,524
Comprehensive income (loss) attributable to noncontrolling interests
Net income attributable to redeemable noncontrolling interest	4	2	8	5
Net income attributable to other noncontrolling interests	2	0	6	1
Other comprehensive (loss) attributable to redeemable noncontrolling interest	(2)	(2)	(6)	(4)
Total comprehensive income attributable to noncontrolling interests	4	0	8	2
SHAREHOLDERS' COMPREHENSIVE INCOME	$ 2,493	$ 1,725	$ 3,088	$ 3,522