Schedule II (STATEMENTS OF CASH FLOWS - Parent Company Only) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2016		Dec. 31, 2015		Dec. 31, 2014
Condensed Financial Statements, Captions [Line Items]
Purchases of fixed maturities available for sale		$ (30,759)		$ (16,040)		$ (15,553)
Sales of fixed maturities available for sale		16,621		10,783		7,482
Net change in short-term investments		12,350		(8,216)		(603)
Net derivative instruments settlements		(168)		(21)		(230)
Net Cash Provided by (Used in) Investing Activities, Continuing Operations		(5,315)		(6,294)		(2,504)
Other		(10)		263		274
Dividends paid on Common Shares		(1,173)		(862)		(862)
Proceeds from issuance of repurchase agreements		2,310		2,029		1,978
Repayments of Short-term Debt		2,311		2,027		1,977
Proceeds from share-based compensation plans		167		131		127
Net increase (decrease) in cash		(790)		1,120		76
Cash – beginning of year		1,775	[1],[2],[3]	655	[2],[4]	579	[4]
Cash – end of year	[2]	985	[5]	1,775	[1],[3]	655	[4]
Chubb limited (Parent Guarantor)
Condensed Financial Statements, Captions [Line Items]
Net cash flows from operating activities		3,618		3,125		541
Net change in short-term investments		0		0		0
Net derivative instruments settlements		0		0		0
Capital contributions to subsidiaries		(2,330)		(2,670)		0
Net Cash Provided by (Used in) Investing Activities, Continuing Operations		(2,330)		(2,670)		0
Other						0
Dividends paid on Common Shares		(1,173)		(862)		(862)
Repayments of Short-term Debt		0				0
Advances (to) from affiliates		404		(228)		260
Net proceeds from (payments to) affiliated notional cash pooling programs		(519)		636		61
Proceeds from share-based compensation plans		0		0		0
Net cash flows (used for) from financing activities		(1,288)		(454)		(541)
Net increase (decrease) in cash		0		1		0
Cash – beginning of year		1	[1],[2],[3]	0	[4]	0	[4]
Cash – end of year		$ 1	[2],[5]	$ 1	[1],[2],[3]	$ 0	[4]

[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, 2015 and 2014, 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, 2016 and 2015, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.

[3] Chubb maintains two notional multicurrency cash pools (Pools) with a third-party bank. Refer to Note 1 f) for additional information. At December 31, 2015, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.

[4] 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, 2014 and 2013, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.

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