Shareholders' equity (Tables)

12 Months Ended

Dec. 31, 2019

Stockholders' Equity Note [Abstract]

Dividends Declared [Table Text Block]

The following table presents dividend distributions per Common Share in Swiss francs (CHF) and U.S. dollars (USD):

	Year Ended December 31
		2019			2018			2017
	CHF	USD		CHF	USD		CHF	USD
Total dividend distributions per common share	2.94	$	2.98	2.84	$	2.90	2.76	$	2.82

Schedule of changes in Common Shares issued and outstanding

	Year Ended December 31
	2019		2018		2017
Shares issued, beginning and end of year	479,783,864		479,783,864		479,783,864
Common Shares in treasury, beginning of year (at cost)	(20,580,486	)	(15,950,685	)	(13,815,148	)
Net shares issued under employee share-based compensation plans	3,210,427		3,089,234		3,731,075
Shares repurchased	(10,442,238	)	(7,719,035	)	(5,866,612	)
Common Shares in treasury, end of year (at cost)	(27,812,297	)	(20,580,486	)	(15,950,685	)
Shares issued and outstanding, end of year	451,971,567		459,203,378		463,833,179

Share Repurchase Program [Table Text Block]

The following table presents repurchases of Chubb's Common Shares conducted in a series of open market transactions under the Board authorizations:

	Year Ended December 31						January 1, 2020 through
(in millions of U.S. dollars, except share data)	2019		2018		2017		February 26, 2020
Number of shares repurchased	10,442,238		7,719,035		5,866,612		947,400
Cost of shares repurchased	$	1,531	$	1,021	$	830	$	151