Income taxes - Income tax rate (Details) - USD ($) $ in Millions		12 Months Ended
Jan. 01, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income taxes
Statutory Federal and Provincial tax rate in Canada		21.00%	21.00%	35.00%
Expected income tax expense (benefit) at statutory rate		$ 16	$ (194)	$ (78)
Impact of US Tax Cuts and Jobs Act of 2017				26
Change in statutory tax rates				(1)
Non-deductible expenses		15	6	9
Tax on international operations		(1)	(45)	(24)
Change in valuation allowance		(108)	96	(93)
Base Erosion and Anti-Abuse Tax		5
Outside basis difference in assets held for sale		78
Tax credits		(1)	(9)	(8)
Non-deductible goodwill impairment			98
Other		1		1
Income tax expense (benefit)		$ 5	$ (48)	$ (168)
Effective income tax rate		6.00%	5.00%	75.00%
US federal corporate tax rate	21.00%			35.00%

Percentage of foreign federal statutory tax rate applicable to pretax income (loss).

No definition available.

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Namespace Prefix:	maxr_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to base erosion and anti-abuse tax.

+ References

No definition available.