SIGNIFICANT ACQUISITIONS AND DIVESTITURES - Fair Value of Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 13, 2019	May 27, 2019	Dec. 31, 2018	Dec. 31, 2017
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net [Abstract]
Goodwill	$ 523,998			$ 447,995	$ 441,361
Zumbro River Brand, Inc.
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net [Abstract]
Cash and cash equivalents		$ 686
Accounts receivable		3,380
Inventories		4,517
Prepaid & other current assets		521
Property, plant and equipment		15,245
Other non-current assets		10
Accounts payable & accrued expenses		(1,538)
Debt		(5,345)
Deferred income taxes		(3,391)
Goodwill		18,073
Amount paid to shareholders		47,058
Zumbro debt paid on purchase date		5,345
Total amount paid on acquisition date		52,403
Zumbro River Brand, Inc. | Customer relationships
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net [Abstract]
Intangible assets		8,200
Zumbro River Brand, Inc. | Developed technology
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net [Abstract]
Intangible assets		4,400
Zumbro River Brand, Inc. | Trade name
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net [Abstract]
Intangible assets		$ 2,300
Chemogas
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net [Abstract]
Cash and cash equivalents			$ 4,412
Accounts receivable			4,176
Inventories			957
Property, plant and equipment			15,972
Other non-current assets			1,491
Accounts payable & accrued expenses			(3,261)
Debt			(12,222)
Other liabilities			(1,030)
Pension obligation (net)			(594)
Deferred income taxes			(12,856)
Goodwill			59,319
Amount paid to shareholders			99,102
Zumbro debt paid on purchase date			12,222
Total amount paid on acquisition date			111,324
Chemogas | Customer relationships
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net [Abstract]
Intangible assets			39,158
Chemogas | Developed technology
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net [Abstract]
Intangible assets			2,461
Chemogas | Trade name
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net [Abstract]
Intangible assets			$ 1,119