EMPLOYEE BENEFIT PLANS Fair value plan assets (Details) - USD ($) $ in Thousands		Dec. 31, 2020		Dec. 31, 2019		Dec. 31, 2018
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		$ 721,005		$ 103,385	[1]	$ 86,556	[1]
Foreign Plan [Member]
Defined Benefit Plan Disclosure
Total investments		100.00%		100.00%
Defined Benefit Plan, Plan Assets, Amount		$ 365,718		$ 103,385	[1]	86,556	[1]
United States
Defined Benefit Plan Disclosure
Total investments		100.00%
Defined Benefit Plan, Plan Assets, Amount		$ 355,287		0		$ 0
Level 1
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		8,049
Level 1 | Foreign Plan [Member]
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		747		224
Level 1 | United States
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		7,302
Level 2
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		19,611
Level 2 | Foreign Plan [Member]
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		19,611		0
Level 2 | United States
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		0
Level 3
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		0
Level 3 | Foreign Plan [Member]
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		0		0
Level 3 | United States
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		0
Fair Value Measured at Net Asset Value Per Share
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	[2]	693,345
Fair Value Measured at Net Asset Value Per Share | Foreign Plan [Member]
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		345,360	[2]	$ 103,161	[3]
Fair Value Measured at Net Asset Value Per Share | United States
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	[2]	347,985
Fixed Income Investments [Member]
Defined Benefit Plan Disclosure
Total investments				44.80%
Fixed Income Investments [Member] | Foreign Plan [Member]
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	[3]			$ 46,309
Fixed Income Investments [Member] | Level 1 | Foreign Plan [Member]
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount				0
Fixed Income Investments [Member] | Level 2
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount				0
Fixed Income Investments [Member] | Level 3
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount				$ 0
Other Investments [Member]
Defined Benefit Plan Disclosure
Total investments				15.20%
Defined Benefit Plan, Plan Assets, Amount		$ 26,361
Other Investments [Member] | Foreign Plan [Member]
Defined Benefit Plan Disclosure
Total investments		5.20%
Defined Benefit Plan, Plan Assets, Amount		$ 19,059		$ 15,704
Other Investments [Member] | United States
Defined Benefit Plan Disclosure
Total investments		2.10%
Defined Benefit Plan, Plan Assets, Amount		$ 7,302
Other Investments [Member] | Level 1
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		8,049
Other Investments [Member] | Level 1 | Foreign Plan [Member]
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		747		224
Other Investments [Member] | Level 1 | United States
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		7,302
Other Investments [Member] | Level 2
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		0
Other Investments [Member] | Level 2 | Foreign Plan [Member]
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		0		0
Other Investments [Member] | Level 2 | United States
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		0
Other Investments [Member] | Level 3
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		0
Other Investments [Member] | Level 3 | Foreign Plan [Member]
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		0		0
Other Investments [Member] | Level 3 | United States
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		0
Other Investments [Member] | Fair Value Measured at Net Asset Value Per Share
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	[2]	18,312
Other Investments [Member] | Fair Value Measured at Net Asset Value Per Share | Foreign Plan [Member]
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		18,312	[2]	$ 15,480	[3]
Other Investments [Member] | Fair Value Measured at Net Asset Value Per Share | United States
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	[2]	0
Defined Benefit Plan, Equity Securities
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		$ 276,635
Defined Benefit Plan, Equity Securities | Foreign Plan [Member]
Defined Benefit Plan Disclosure
Total investments		38.10%		40.00%
Defined Benefit Plan, Plan Assets, Amount		$ 139,537
Defined Benefit Plan, Equity Securities | United States
Defined Benefit Plan Disclosure
Total investments		38.60%
Defined Benefit Plan, Plan Assets, Amount		$ 137,098
Defined Benefit Plan, Equity Securities | Level 1
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		0
Defined Benefit Plan, Equity Securities | Level 1 | Foreign Plan [Member]
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		0
Defined Benefit Plan, Equity Securities | Level 1 | United States
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		0
Defined Benefit Plan, Equity Securities | Level 2
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		0
Defined Benefit Plan, Equity Securities | Level 2 | Foreign Plan [Member]
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		0
Defined Benefit Plan, Equity Securities | Level 2 | United States
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		0
Defined Benefit Plan, Equity Securities | Level 3
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		0
Defined Benefit Plan, Equity Securities | Level 3 | Foreign Plan [Member]
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		0
Defined Benefit Plan, Equity Securities | Level 3 | United States
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		0
Defined Benefit Plan, Equity Securities | Fair Value Measured at Net Asset Value Per Share
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	[2]	276,635
Defined Benefit Plan, Equity Securities | Fair Value Measured at Net Asset Value Per Share | Foreign Plan [Member]
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	[2]	139,537
Defined Benefit Plan, Equity Securities | Fair Value Measured at Net Asset Value Per Share | United States
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	[2]	137,098
US Treasury and Government
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		78,808
US Treasury and Government | Foreign Plan [Member]
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		$ 0
US Treasury and Government | United States
Defined Benefit Plan Disclosure
Total investments		22.20%
Defined Benefit Plan, Plan Assets, Amount		$ 78,808
US Treasury and Government | Level 1
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		0
US Treasury and Government | Level 1 | Foreign Plan [Member]
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		0
US Treasury and Government | Level 1 | United States
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		0
US Treasury and Government | Level 2
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		0
US Treasury and Government | Level 2 | Foreign Plan [Member]
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		0
US Treasury and Government | Level 2 | United States
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		0
US Treasury and Government | Level 3
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		0
US Treasury and Government | Level 3 | Foreign Plan [Member]
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		0
US Treasury and Government | Level 3 | United States
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		0
US Treasury and Government | Fair Value Measured at Net Asset Value Per Share
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	[2]	78,808
US Treasury and Government | Fair Value Measured at Net Asset Value Per Share | Foreign Plan [Member]
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	[2]	0
US Treasury and Government | Fair Value Measured at Net Asset Value Per Share | United States
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	[2]	78,808
Corporate Debt Securities
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		$ 45,501
Corporate Debt Securities | Foreign Plan [Member]
Defined Benefit Plan Disclosure
Total investments		5.90%
Defined Benefit Plan, Plan Assets, Amount		$ 21,677
Corporate Debt Securities | United States
Defined Benefit Plan Disclosure
Total investments		6.70%
Defined Benefit Plan, Plan Assets, Amount		$ 23,824
Corporate Debt Securities | Level 1
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		0
Corporate Debt Securities | Level 1 | Foreign Plan [Member]
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		0
Corporate Debt Securities | Level 1 | United States
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		0
Corporate Debt Securities | Level 2
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		0
Corporate Debt Securities | Level 2 | Foreign Plan [Member]
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		0
Corporate Debt Securities | Level 2 | United States
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		0
Corporate Debt Securities | Level 3
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		0
Corporate Debt Securities | Level 3 | Foreign Plan [Member]
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		0
Corporate Debt Securities | Level 3 | United States
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		0
Corporate Debt Securities | Fair Value Measured at Net Asset Value Per Share
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	[2]	45,501
Corporate Debt Securities | Fair Value Measured at Net Asset Value Per Share | Foreign Plan [Member]
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	[2]	21,677
Corporate Debt Securities | Fair Value Measured at Net Asset Value Per Share | United States
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	[2]	23,824
Other Debt Obligations
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		$ 204,016
Other Debt Obligations | Foreign Plan [Member]
Defined Benefit Plan Disclosure
Total investments		40.60%
Defined Benefit Plan, Plan Assets, Amount		$ 148,469
Other Debt Obligations | United States
Defined Benefit Plan Disclosure
Total investments		15.60%
Defined Benefit Plan, Plan Assets, Amount		$ 55,547
Other Debt Obligations | Level 1
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		0
Other Debt Obligations | Level 1 | Foreign Plan [Member]
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		0
Other Debt Obligations | Level 1 | United States
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		0
Other Debt Obligations | Level 2
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		0
Other Debt Obligations | Level 2 | Foreign Plan [Member]
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		0
Other Debt Obligations | Level 2 | United States
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		0
Other Debt Obligations | Level 3
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		0
Other Debt Obligations | Level 3 | Foreign Plan [Member]
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		0
Other Debt Obligations | Level 3 | United States
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		0
Other Debt Obligations | Fair Value Measured at Net Asset Value Per Share
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	[2]	204,016
Other Debt Obligations | Fair Value Measured at Net Asset Value Per Share | Foreign Plan [Member]
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	[2]	148,469
Other Debt Obligations | Fair Value Measured at Net Asset Value Per Share | United States
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	[2]	55,547
Real Estate Funds
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		$ 70,073
Real Estate Funds | Foreign Plan [Member]
Defined Benefit Plan Disclosure
Total investments		4.80%
Defined Benefit Plan, Plan Assets, Amount		$ 17,365
Real Estate Funds | United States
Defined Benefit Plan Disclosure
Total investments		14.80%
Defined Benefit Plan, Plan Assets, Amount		$ 52,708
Real Estate Funds | Level 1
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		0
Real Estate Funds | Level 1 | Foreign Plan [Member]
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		0
Real Estate Funds | Level 1 | United States
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		0
Real Estate Funds | Level 2
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		0
Real Estate Funds | Level 2 | Foreign Plan [Member]
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		0
Real Estate Funds | Level 2 | United States
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		0
Real Estate Funds | Level 3
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		0
Real Estate Funds | Level 3 | Foreign Plan [Member]
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		0
Real Estate Funds | Level 3 | United States
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		0
Real Estate Funds | Fair Value Measured at Net Asset Value Per Share
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	[2]	70,073
Real Estate Funds | Fair Value Measured at Net Asset Value Per Share | Foreign Plan [Member]
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	[2]	17,365
Real Estate Funds | Fair Value Measured at Net Asset Value Per Share | United States
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	[2]	52,708
Insurance product
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		$ 19,611
Insurance product | Foreign Plan [Member]
Defined Benefit Plan Disclosure
Total investments		5.40%
Defined Benefit Plan, Plan Assets, Amount		$ 19,611
Insurance product | United States
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		0
Insurance product | Level 1
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		0
Insurance product | Level 1 | Foreign Plan [Member]
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		0
Insurance product | Level 1 | United States
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		0
Insurance product | Level 2
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		19,611
Insurance product | Level 2 | Foreign Plan [Member]
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		19,611
Insurance product | Level 2 | United States
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		0
Insurance product | Level 3
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		0
Insurance product | Level 3 | Foreign Plan [Member]
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		0
Insurance product | Level 3 | United States
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		0
Insurance product | Fair Value Measured at Net Asset Value Per Share
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	[2]	0
Insurance product | Fair Value Measured at Net Asset Value Per Share | Foreign Plan [Member]
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	[2]	0
Insurance product | Fair Value Measured at Net Asset Value Per Share | United States
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	[2]	$ 0
Defined Benefit Plan, Equity Securities, US | Foreign Plan [Member]
Defined Benefit Plan Disclosure
Total investments				5.00%
Defined Benefit Plan, Plan Assets, Amount	[3]			$ 5,160
Defined Benefit Plan, Equity Securities, US | Level 1 | Foreign Plan [Member]
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount				0
Defined Benefit Plan, Equity Securities, US | Level 2
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount				0
Defined Benefit Plan, Equity Securities, US | Level 3
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount				$ 0
Defined Benefit Plan, Equity Securities, Non-US | Foreign Plan [Member]
Defined Benefit Plan Disclosure
Total investments				22.50%
Defined Benefit Plan, Plan Assets, Amount	[3]			$ 23,239
Defined Benefit Plan, Equity Securities, Non-US | Level 1 | Foreign Plan [Member]
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount				0
Defined Benefit Plan, Equity Securities, Non-US | Level 2
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount				0
Defined Benefit Plan, Equity Securities, Non-US | Level 3
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount				$ 0
Equity Securities, Canadian | Foreign Plan [Member]
Defined Benefit Plan Disclosure
Total investments				12.50%
Defined Benefit Plan, Plan Assets, Amount	[3]			$ 12,973
Equity Securities, Canadian | Level 1 | Foreign Plan [Member]
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount				0
Equity Securities, Canadian | Level 2
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount				0
Equity Securities, Canadian | Level 3
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount				$ 0

[1] For 2019, the changes in benefit obligations, plan assets and funded status relate to the EECOL Plan and the EECOL SERP

[2] Investments measured at fair value using the NAV per share practical expedient have not been classified in the fair value hierarchy. The amounts presented in the table are intended to reconcile the fair value hierarchy to the total fair value of plan assets

[3] Investments measured at fair value using the NAV per share practical expedient have not been classified in the fair value hierarchy. The amounts presented in the table are intended to reconcile the fair value hierarchy to the total fair value of plan assets.