PENSION, POST-RETIREMENT AND OTHER LONG-TERM EMPLOYEE BENEFIT PLANS - Fair Value of Plan Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Disclosure of defined benefits plan
Defined benefit obligations	$ 103,227	$ 94,055
Fair value of plan assets	(86,425)	(79,003)
Deficit in plans	16,802	15,052
U.S.
Disclosure of defined benefits plan
Defined benefit obligations	81,883	75,571
Fair value of plan assets	(69,649)	(63,877)
Deficit in plans	12,234	11,694
Canada
Disclosure of defined benefits plan
Defined benefit obligations	21,344	18,484
Fair value of plan assets	(16,776)	(15,126)
Deficit in plans	$ 4,568	$ 3,358

The present value, without deducting any plan assets, of expected future payments required to settle the obligation resulting from employee service in the current and prior periods. [Refer: Plan assets, at fair value]

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 19
-IssueDate 2020-01-01
-Paragraph 57
-Subparagraph a
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=19&code=ifrs-tx-2020-en-r&anchor=para_57_a&doctype=Standard
-URIDate 2020-01-01

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Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes of the table.

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The fair value of defined benefit plan assets. Plan assets comprise assets held by a long-term employee benefit fund and qualifying insurance policies. [Refer: At fair value [member]]

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- Definition

The fair value of any plan assets, less the present value of the defined benefit obligation. [Refer: Plan assets [member]]

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