Summary of significant accounting policies Summary of Significant Accounting Policies (Tables) (Tables)

12 Months Ended

Dec. 31, 2020

Cash and Cash Equivalents [Abstract]

Schedule of Cash and Cash Equivalents [Table Text Block]

The following table provides a reconciliation of cash and restricted cash reported within the Consolidated balance sheets that total to the amounts shown in the Consolidated statements of cash flows:

	December 31
(in millions of U.S. dollars)	2020		2019		2018
Cash	$	1,747	$	1,537	$	1,247
Restricted cash	89		109		93
Total cash and restricted cash shown in the Consolidated statements of cash flows	$	1,836	$	1,646	$	1,340