Earnings per share (Tables)

12 Months Ended

Dec. 31, 2015

Earnings Per Share [Abstract]

Schedule Of Earnings Per Share, Basic And Diluted

	Years Ended December 31
(in millions of U.S. dollars, except share and per share data)	2015		2014		2013
Numerator:
Net income	$	2,834	$	2,853	$	3,758
Denominator:
Denominator for basic earnings per share:
Weighted-average shares outstanding	325,589,361		335,609,899		340,906,490
Denominator for diluted earnings per share:
Share-based compensation plans	3,246,017		3,376,388		3,241,085
Weighted-average shares outstanding       and assumed conversions	328,835,378		338,986,287		344,147,575
Basic earnings per share	$	8.71	$	8.50	$	11.02
Diluted earnings per share	$	8.62	$	8.42	$	10.92
Potential anti-dilutive share conversions	1,601,668		1,024,788		1,031,297