BUSINESS COMBINATIONS - Assets Acquired and Liabilities Assumed (Details) - USD ($)	3 Months Ended
	Mar. 31, 2022	Dec. 31, 2021
Business Acquisition [Line Items]
Goodwill	$ 1,221,399,000	$ 1,227,042,000
Measurement Period Adjustments, Goodwill	(6,557,000)
HydroChemPSC
Business Acquisition [Line Items]
Accounts receivable, including unbilled receivables	131,605,000	131,924,000
Measurement Period Adjustments, Accounts receivable, including unbilled receivables	(319,000)
Inventories and supplies	3,162,000	3,162,000
Prepaid expenses and other current assets	16,284,000	16,016,000
Measurement Period Adjustments, Prepaid expenses and other current assets	268,000
Property, plant and equipment	313,540,000	313,540,000
Other intangibles	289,000,000	289,000,000
Operating lease right-of-use assets	34,415,000	34,347,000
Measurement Period Adjustments, Operating lease right-of-use assets	68,000
Other non-current assets	1,043,000	1,045,000
Measurement Period Adjustments, Other non-current assets	(2,000)
Current liabilities	(116,522,000)	(115,704,000)
Measurement Period Adjustments, Current liabilities	(818,000)
Current portion of operating lease liabilities	(11,277,000)	(11,659,000)
Measurement Period Adjustments, Current portion of operating lease liabilities	382,000
Operating lease liabilities, less current portion	(26,344,000)	(26,128,000)
Measurement Period Adjustments, Operating lease liabilities, less current portion	(216,000)
Deferred tax liabilities	(83,472,000)	(85,908,000)
Measurement Period Adjustments, Deferred tax liabilities	2,436,000
Other long-term liabilities	(2,927,000)	(2,685,000)
Measurement Period Adjustments, Other long-term liabilities	(242,000)
Total identifiable net assets	548,507,000	546,950,000
Measurement Period Adjustments, Total identifiable net assets	1,557,000
Goodwill	676,906,000	683,463,000
Measurement Period Adjustments, Goodwill	(6,557,000)
Total purchase price	1,225,413,000	$ 1,230,413,000
Measurement Period Adjustments, Total purchase price	(5,000,000)
Goodwill, deductible for tax purposes	$ 0