Consolidated Statement of Cash Flows (Unaudited) - USD ($) $ in Millions		6 Months Ended
		Jun. 30, 2018	Jun. 30, 2017
Cash flows from operating activities
Net income		$ 1,193	$ 1,212
Adjustments to reconcile net income to net cash provided by operating activities:
Net realized investment gains	[1]	(25)	(85)
Depreciation and amortization		411	409
Deferred federal income tax expense (benefit)		(70)	106
Amortization of deferred acquisition costs		2,142	2,035
Equity in income from other investments		(169)	(210)
Premiums receivable		(660)	(609)
Reinsurance recoverables		29	157
Deferred acquisition costs		(2,284)	(2,157)
Claims and claim adjustment expense reserves		435	498
Unearned premium reserves		879	689
Other operating activities		(183)	(291)
Net cash provided by operating activities		1,698	1,754
Cash flows from investing activities
Proceeds from maturities of fixed maturities		3,657	4,300
Proceeds from sales of investments:
Fixed maturities		2,607	563
Equity securities		92
Equity securities			200
Real estate investments			20
Other investments		189	233
Purchases of investments:
Fixed maturities		(7,952)	(5,673)
Equity securities		(60)
Equity securities			(166)
Real estate investments		(44)	(26)
Other investments		(275)	(259)
Net (purchases) sales of short-term securities		1,202	(424)
Securities transactions in course of settlement		279	170
Other investing activities		(152)	(128)
Net cash used in investing activities		(457)	(1,190)
Cash flows from financing activities
Treasury stock acquired — share repurchase authorization		(700)	(700)
Treasury stock acquired — net employee share-based compensation		(51)	(61)
Dividends paid to shareholders		(404)	(389)
Payment of debt		(600)	(207)
Issuance of debt		491	689
Issuance of common stock — employee share options		98	118
Net cash used in financing activities		(1,166)	(550)
Effect of exchange rate changes on cash		(4)	7
Net increase in cash		71	21
Cash at beginning of year		344	307
Cash at end of period		415	328
Supplemental disclosure of cash flow information
Income taxes paid		238	323
Interest paid		$ 175	$ 178

[1] Total other-than-temporary impairment (OTTI) losses were $(1) million and $(5) million for the three months ended June 30, 2018 and 2017, respectively, and $(1) million and $(6) million for the six months ended June 30, 2018 and 2017, respectively. Of total OTTI, credit losses of $(1) million and $(5) million for the three months ended June 30, 2018 and 2017, respectively, and $(1) million and $(7) million for the six months ended June 30, 2018 and 2017, respectively, were recognized in net realized investment gains. In addition, unrealized gains (losses) from other changes in total OTTI of $0 million for each of the three months ended June 30, 2018 and 2017, respectively, and $0 million and $1 million for the six months ended June 30, 2018 and 2017, respectively, were recognized in other comprehensive income (loss) as part of changes in net unrealized gains (losses) on investment securities having credit losses recognized in the consolidated statement of income.