Income Tax Expense (Recovery) - Unrecognized Tax Benefits (Detail) - USD ($) $ in Thousands	9 Months Ended
Sep. 30, 2020	Sep. 30, 2019
Income Tax Disclosure [Abstract]
Beginning balance	$ 62,958	$ 40,556
Increases for positions related to the current year	8,608	2,106
Increase for positions taken in prior periods		4,121
Decrease for positions taken in prior periods	14,564
Freight tax liability, Decrease Resulting from Settlements with Taxing Authorities	(9,372)	0
Decrease related to statute limitations	2,372	0
Ending balance	$ 45,258	$ 46,783

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Amount of unrecognized tax benefits.

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Amount of decrease in unrecognized tax benefits resulting from tax positions taken in prior period tax returns.

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Amount of decrease in unrecognized tax benefits resulting from settlements with taxing authorities.

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Amount of increase in unrecognized tax benefits resulting from tax positions that have been or will be taken in current period tax return.

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Amount of increase in unrecognized tax benefits resulting from tax positions taken in prior period tax returns.

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Amount of decrease in unrecognized tax benefits resulting from lapses of applicable statutes of limitations.

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