Consolidated Statement of Income (Unaudited) - USD ($) shares in Millions, $ in Millions		3 Months Ended
		Mar. 31, 2018	Mar. 31, 2017
Revenues
Premiums		$ 6,537	$ 6,183
Net investment income		603	610
Fee income		103	113
Net realized investment gains (losses)	[1]	(11)	5
Other revenues		54	31
Total revenues		7,286	6,942
Claims and expenses
Claims and claim adjustment expenses		4,296	4,094
Amortization of deferred acquisition costs		1,061	1,003
General and administrative expenses		1,062	996
Interest expense		89	89
Total claims and expenses		6,508	6,182
Income before income taxes		778	760
Income tax expense		109	143
Net income		$ 669	$ 617
Net income per share
Basic (in dollars per share)		$ 2.45	$ 2.19
Diluted (in dollars per share)		$ 2.42	$ 2.17
Weighted average number of common shares outstanding
Basic (in shares)		271.0	279.7
Diluted (in shares)		273.9	282.4
Cash dividends declared per common share (in dollars per share)		$ 0.72	$ 0.67

[1] Total other-than-temporary impairment (OTTI) gains (losses) were $0 and $(1) million for the three months ended March 31, 2018 and 2017, respectively. Of total OTTI, credit losses of $0 and $(2) million for the three months ended March 31, 2018 and 2017, respectively, were recognized in net realized investment gains (losses). In addition, unrealized gains from other changes in total OTTI of $0 and $1 million for the three months ended March 31, 2018 and 2017, respectively, were recognized in other comprehensive income (loss) as part of changes in net unrealized gains on investment securities having credit losses recognized in the consolidated statement of income.