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EMPLOYEE BENEFIT PLANS - Plan assets using fair value hierarchy (Details) - Retirement Income Plan - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
EMPLOYEE BENEFIT PLANS
Investments Measured at Net Asset Value		$ 514
Investments at Fair Value	$ 7,351	7,314
Cash and Cash Equivalents
EMPLOYEE BENEFIT PLANS
Total Assets in the Fair Value Hierarchy	138	92
Cash and Cash Equivalents | Quoted prices in active markets for identical assets (Level 1)
EMPLOYEE BENEFIT PLANS
Total Assets in the Fair Value Hierarchy	138	92
Fixed Income Securities
EMPLOYEE BENEFIT PLANS
Total Assets in the Fair Value Hierarchy	7,213	6,708
Fixed Income Securities | Significant other observable inputs (Level 2)
EMPLOYEE BENEFIT PLANS
Total Assets in the Fair Value Hierarchy	7,213	6,708
Investment
EMPLOYEE BENEFIT PLANS
Total Assets in the Fair Value Hierarchy	7,351	6,800
Investment | Quoted prices in active markets for identical assets (Level 1)
EMPLOYEE BENEFIT PLANS
Total Assets in the Fair Value Hierarchy	138	92
Investment | Significant other observable inputs (Level 2)
EMPLOYEE BENEFIT PLANS
Total Assets in the Fair Value Hierarchy	$ 7,213	$ 6,708

X

- Definition

Fair value of investment other than investment in equity security, investment in debt security and equity method investment. Includes, but is not limited to, investment in certain entities that calculate net asset value per share. Example includes, but is not limited to, investment in hedge fund, venture capital fund, private equity fund, and real estate partnership or fund.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 6A
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=117815213&loc=SL6742756-110258

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 35
-Paragraph 54B
-URI http://asc.fasb.org/extlink&oid=117332851&loc=SL7495116-110257

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- Definition

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+ References

No definition available.

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- Definition

Amount of investment within defined benefit plan asset category.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (d)(ii)
-URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920

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- Definition

Fair value portion of investment securities, including, but not limited to, marketable securities, derivative financial instruments, and investments accounted for under the equity method.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258

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