Earnings per share (Tables)

12 Months Ended

Dec. 31, 2017

Earnings Per Share [Abstract]

Schedule Of Earnings Per Share, Basic And Diluted

	Year Ended December 31
(in millions of U.S. dollars, except share and per share data)	2017		2016		2015
Numerator:
Net income	$	3,861	$	4,135	$	2,834
Denominator:
Denominator for basic earnings per share:
Weighted-average shares outstanding	467,145,716		462,519,789		325,589,361
Denominator for diluted earnings per share:
Share-based compensation plans	4,051,185		3,429,610		3,246,017
Weighted-average shares outstanding       and assumed conversions	471,196,901		465,949,399		328,835,378
Basic earnings per share	$	8.26	$	8.94	$	8.71
Diluted earnings per share	$	8.19	$	8.87	$	8.62
Potential anti-dilutive share conversions	1,776,025		1,206,828		1,601,668