Consolidated Statements Of Cash Flows - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2019		Dec. 31, 2018		Dec. 31, 2017
Cash flows from operating activities
Net income		$ 4,454		$ 3,962		$ 3,861
Adjustments to reconcile net income to net cash flows from operating activities
Net Realized Gains Losses		530		652		(84)
Amortization of premiums/discounts on fixed maturities		395		592		694
Amortization of purchased intangibles		305		339		260
Deferred income taxes		(97)		16		(527)
Unpaid losses and loss expenses		(257)		570		2,137
Unearned premiums		1,051		654		264
Future policy benefits		215		235		217
Insurance and reinsurance balances payable		(302)		722		271
Accounts payable, accrued expenses, and other liabilities		(207)		375		(517)
Income taxes payable		(7)		161		(365)
Insurance and reinsurance balances receivable		(270)		(981)		(243)
Reinsurance recoverable		838		(1,165)		(1,248)
Deferred policy acquisition costs		(344)		(301)		(317)
Other		38		(351)		100
Net cash flows from operating activities		6,342		5,480		4,503
Cash flows from investing activities
Purchases of fixed maturities available for sale		(25,846)		(24,700)		(25,720)
Purchases of to be announced mortgage-backed securities		0		(35)		(27)
Purchases of fixed maturities held to maturity		(229)		(456)		(352)
Purchases of equity securities		(531)		(207)		(173)
Sales of fixed maturities available for sale		13,110		14,001		13,228
Sales of to be announced mortgage-backed securities		6		29		27
Sales of equity securities		611		315		187
Maturities and redemptions of fixed maturities available for sale		9,039		7,352		10,425
Maturities and redemptions of fixed maturities held to maturity		946		1,124		879
Net change in short-term investments		(1,117)		516		(537)
Net derivative instruments settlements		(703)		16		(265)
Private equity contributions		(1,315)		(1,337)		(648)
Private equity distributions		1,390		980		1,084
Acquisition of subsidiaries (net of cash acquired of $45, nil, and nil)		(29)		0		0
Other		(1,237)		(533)		(530)
Net Cash Provided by (Used in) Investing Activities		(5,905)		(2,935)		(2,422)
Cash flows from financing activities
Dividends paid on Common Shares		(1,354)		(1,337)		(1,308)
Common Shares repurchased		(1,530)		(1,044)		(801)
Proceeds from issuance of long-term debt		2,828		2,171		0
Proceeds from issuance of repurchase agreements		2,817		2,029		2,353
Repayments of Long-term Debt		(510)		(2,001)		(501)
Repayment of repurchase agreements		(2,817)		(2,019)		(2,348)
Proceeds from share-based compensation plans		204		115		151
Policyholder contract deposits		514		453		442
Policyholder contract withdrawals		(303)		(358)		(307)
Net cash flows (used for) from financing activities		(151)		(1,991)		(2,319)
Effect of foreign currency rate changes on cash and restricted cash		20		(65)		1
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect		306		489		(237)
Cash and restricted cash - beginning of year		1,340	[1],[2]	851	[2],[3]	1,088	[3]
Cash and restricted cash - end of year	[2]	1,646		1,340	[1]	851	[3]
Supplemental cash flow information
Taxes paid		912		503		736
Interest paid		$ 512		$ 621		$ 644

[1] Chubb maintains two notional multi-currency cash pools (Pools) with a third-party bank. Refer to Note 1 f) for additional information. At December 31, 2018 and 2017, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.

[2] Chubb maintains two notional multi-currency cash pools (Pools) with a third-party bank. Refer to Note 1 f) for additional information. At December 31, 2018, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.

[3] Chubb maintains two notional multi-currency cash pools (Pools) with a third-party bank. Refer to Note 1 f) for additional information. At December 31, 2017 and 2016, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.