Schedule II (STATEMENTS OF CASH FLOWS - Parent Company Only) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Condensed Financial Statements, Captions [Line Items]
Net Cash Provided by (Used) in Operating Activities, Total		$ 16,182	$ 12,632	$ 11,258
Other		(1,412)	(889)	(560)
Net Cash Provided by (Used in) Investing Activities		(13,923)	(7,648)	(5,654)
Dividends paid on Common Shares		(1,436)	(1,394)	(1,375)
Common Shares repurchased		(1,801)	(2,411)	(2,894)
Net cash flows (used for) from financing activities		(2,181)	(4,489)	(5,142)
Effect of foreign currency rate changes on cash and restricted cash		(150)	(1)	(146)
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect		(72)	494	316
Chubb limited (Parent Guarantor)
Condensed Financial Statements, Captions [Line Items]
Net Cash Provided by (Used) in Operating Activities, Total	[1]	1,755	3,273	7,831
Capital redemption (contribution)		2,000	0	(4,046)
Net Cash Provided by (Used in) Investing Activities		2,000	0	(4,046)
Dividends paid on Common Shares		(1,436)	(1,394)	(1,375)
Common Shares repurchased		(1,801)	(2,411)	(2,894)
Repayment of intercompany loans		99	231	279
Net proceeds from (payments to) affiliated notional cash pooling programs	[2]	(317)	342	245
Net cash flows (used for) from financing activities		(3,455)	(3,232)	(3,745)
Effect of foreign currency rate changes on cash and restricted cash		6	(4)	(1)
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect		306	37	39
Cash – beginning of year		77	40	1
Cash – end of year		383	77	40
Cash dividend paid by Affiliates	[1]	$ 1,800	$ 3,300	$ 7,700

[1] Includes cash dividends received from subsidiaries of $1.8 billion, $3.3 billion, and $7.7 billion in 2024, 2023, and 2022, respectively.

[2] Chubb maintains two notional multicurrency cash pools (Pools) with a third-party bank. Refer to Note 1 i) for additional information.