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PENSION AND POST-RETIREMENT PLANS - DEFINED CONTRIBUTION PLANS (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
401(K) plan
Defined Contribution Plans
Employer matching contribution (as a percent)	3.00%
Employer matching contribution expenses	$ 3.0	$ 2.9	$ 2.4
Profit sharing plan
Defined Contribution Plans
Profit sharing expense recorded	$ 2.2	$ 0.5	$ 1.4

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- References

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- Definition

Represents the amount of the profit sharing expenses recorded during the period for defined contribution plans.

+ References

No definition available.

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- Definition

Amount of cost for defined contribution plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 70
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=49170846&loc=d3e28014-114942

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- Definition

Percentage of employees' gross pay for which the employer contributes a matching contribution to a defined contribution plan.

+ References

No definition available.

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