EMPLOYEE BENEFIT PLANS (Employee 401(k) Plan, Employee Pension Plan, Registered Retirement Savings Plan and Employee Stock Purchase Plan) (Details) - USD ($)		12 Months Ended
Sep. 15, 2015	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Contribution Plan Disclosure [Line Items]
Maximum percentage of employee total compensation matched by employer (in hundredths)		100.00%	100.00%	100.00%
Maximum annual employee contribution		4.00%	4.00%	4.00%
Company match to employee contributions		$ 15,000,000	$ 12,000,000	$ 12,000,000
Administrative expense		$ 0	$ 0	$ 0
Employee Stock Purchase Plan
Defined Contribution Plan Disclosure [Line Items]
Percentage of purchase price of company's common stock to the market price		90.00%
Increase in shares of common stock issued pursuant to stock plan (in shares)	100,000
Shares available, employee stock purchase plan (in shares)		38,591	51,584
Shares of company's common stock purchased during the period (in shares)		12,993	13,590
Registered Retirement Savings Plan
Defined Contribution Plan Disclosure [Line Items]
Maximum percentage of employee total compensation matched by employer (in hundredths)		100.00%	100.00%	100.00%
Maximum annual employee contribution		4.00%	4.00%	4.00%
Company match to employee contributions		$ 100,000
Foreign Plan \| Pension Plan
Defined Contribution Plan Disclosure [Line Items]
Maximum percentage of employee total compensation matched by employer (in hundredths)		6.00%	6.00%	6.00%
Company match to employee contributions		$ 900,000	$ 600,000	$ 500,000

The increase in the number of shares of common stock for issuance under the company stock plan.

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- Definition

The percentage of market price that eligible employees under the plan can purchase company stock.

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- Definition

Number of shares available as a result of an employee stock purchase plan.

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- Definition

Amount of administrative expense incurred by defined contribution plan.

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

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- Definition

Percentage employer matches of the employee's percentage contribution matched.

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- Definition

Maximum percentage of employee gross pay the employee may contribute to a defined contribution plan.

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- Definition

Number of shares issued during the period as a result of an employee stock purchase plan.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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