Shareholders' equity (Tables)

12 Months Ended

Dec. 31, 2018

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
		2018			2017			2016
	CHF	USD		CHF	USD		CHF	USD
Total dividend distributions per common share	2.84	$	2.90	2.76	$	2.82	2.70	$	2.74

Schedule of changes in Common Shares issued and outstanding

	Year Ended December 31
	2018		2017		2016
Shares issued, beginning of year	479,783,864		479,783,864		342,832,412
Shares issued for Chubb Corp acquisition	—		—		136,951,452
Shares issued, end of year	479,783,864		479,783,864		479,783,864
Common Shares in treasury, end of year (at cost)	(20,580,486	)	(15,950,685	)	(13,815,148	)
Shares issued and outstanding, end of year	459,203,378		463,833,179		465,968,716

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, 2019 through
(in millions of U.S. dollars, except share data)	2018		2017		2016		February 27, 2019
Number of shares repurchased	7,719,035		5,866,612		—		1,328,754
Cost of shares repurchased	$	1,021	$	830	$	—	$	174