Consolidated Statements Of Operations and Comprehensive Income - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Revenues
Net premiums written	$ 7,977	$ 7,313
Increase in unearned premiums	(183)	(176)
Net premiums earned	7,794	7,137
Net investment income	861	836
Net realized gains (losses):
Other-than-temporary impairment (OTTI) losses gross	0	(13)
Portion of OTTI losses recognized in other comprehensive income (OCI)	0	0
Net OTTI losses recognized in income	0	(13)
Net realized gains (losses) excluding OTTI losses	0	(84)
Net Realized Gains Losses	(958)	(97)
Total revenues	7,697	7,876
Expenses
Losses and loss expenses	4,485	4,098
Policy benefits	129	196
Policy acquisition costs	1,615	1,464
Administrative expenses	741	710
Interest expense	132	140
Other (income) expense	55	(39)
Amortization of purchased intangibles	73	76
Chubb integration expenses	0	3
Total expenses	7,230	6,648
Income before income tax	467	1,228
Income tax expense (benefit) (includes $(40) and $(6) on reclassified unrealized gains and losses)	215	188
Net income	252	1,040
Other comprehensive income (loss)
Unrealized appreciation (depreciation)	(2,479)	1,845
Reclassification adjustment for net realized (gains) losses included in net income	319	44
Unrealized appreciation (Depreciation) after reclassification adjustment	(2,160)	1,889
Change in:
Cumulative foreign currency translation adjustment	(859)	147
Postretirement benefit liability adjustment	(14)	(27)
Other comprehensive income (loss), before income tax	(3,033)	2,009
Income tax (expense) benefit related to OCI items	321	(331)
Other comprehensive income (loss)	(2,712)	1,678
Comprehensive income (loss)	$ (2,460)	$ 2,718
Earnings per share
Basic earnings per share	$ 0.56	$ 2.27
Diluted earnings per share	$ 0.55	$ 2.25