Schedule II (BALANCE SHEETS - Parent Company Only) (Details) - USD ($) $ in Millions		Dec. 31, 2019		Dec. 31, 2018		Dec. 31, 2017	Dec. 31, 2016
Assets
Investments in subsidiaries and affiliates on equity basis		$ 0		$ 0
Cash		1,537	[1]	1,247	[2]	$ 728
Due from subsidiaries and affiliates, net		0		0
Other assets		7,581		6,531
Total assets		176,943		167,771
Liabilities
Affiliated notional cash pooling program	[2]			0
Accounts payable, accrued expenses, and other liabilities		11,773		10,472
Total liabilities		121,612		117,459
Stockholders' Equity Attributable to Parent [Abstract]
Common Shares		11,121		11,121
Common Shares in treasury (27,812,297 and 20,580,486 shares)		(3,754)		(2,618)
Retained earnings		36,142		31,700
Accumulated other comprehensive income		619		(2,448)
Total shareholders' equity		55,331		50,312		51,172
Total liabilities and shareholders’ equity		176,943		167,771
Parent Company Only
Assets
Investments in subsidiaries and affiliates on equity basis		50,853		43,531
Total investments		50,853		43,531
Cash		2	[1]	1	[2]	$ 3	$ 1
Due from subsidiaries and affiliates, net		4,776		7,074
Other assets		12		3
Total assets		55,643		50,609
Liabilities
Affiliated notional cash pooling program	[3]	0		35	[2]
Accounts payable, accrued expenses, and other liabilities		312		262
Total liabilities		312		297
Stockholders' Equity Attributable to Parent [Abstract]
Common Shares		11,121		11,121
Common Shares in treasury (27,812,297 and 20,580,486 shares)		(3,754)		(2,618)
Additional paid-in capital		11,203		12,557
Retained earnings		36,142		31,700
Accumulated other comprehensive income		619		(2,448)
Total shareholders' equity		55,331		50,312
Total liabilities and shareholders’ equity		$ 55,643		$ 50,609

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

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