Other comprehensive income (Tables)

12 Months Ended

Dec. 31, 2022

Disclosure of analysis of other comprehensive income by item [abstract]

Schedule of other comprehensive income


						Items that may subsequently be reclassified to income												Item never reclassified to income
(millions)						Change in unrealized fair value of derivatives						Cumulative foreign currency translation adjustment						Employee defined benefit plan re- measurements						Accumulated other comprehensive income
Accumulated balance as at January 1, 2020						$	(1)					$	19					$	(3)					$	15
Other comprehensive income (loss)
Amount arising						(51)						124						—						73
Income taxes						1						—						—						1
Net						(50)						124						—						74
Accumulated balance as at December 31, 2020						$	(51)					$	143					$	(3)					$	89
Other comprehensive income (loss)
Amount arising						41						(95)						—						(54)
Income taxes						(1)						—						—						(1)
Net						40						(95)						—						(55)
Accumulated balance as at December 31, 2021						$	(11)					$	48					$	(3)					$	34
Other comprehensive income (loss)
Amount arising						48						(89)						3						(38)
Income taxes						(5)						—						—						(5)
Net						$	43					$	(89)					$	3					$	(43)
Accumulated balance as at December 31, 2022						$	32					$	(41)					$	—					$	(9)