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COMMON SHARES - Narrative (Details) $ in Millions			3 Months Ended
COMMON SHARES - Narrative (Details) $ in Millions	Oct. 03, 2022 USD ($) customer shares	May 11, 2022 USD ($)	Sep. 30, 2022 USD ($) shares	Dec. 31, 2021 shares
Business Acquisition [Line Items]
Sale of stock, issuance of common stock, maximum \| $		$ 1,200.0
Sale of stock, consideration received on transaction \| $			$ 197.1
Sale of stock, number of shares issued in transaction (in shares)			2,165,671
Treasury stock (in shares)			12,635,324	13,415,206
Common stock outstanding (in shares)			347,348,749	344,403,196
The Torrington Water Company (TWC) \| Subsequent Event \| Subsidiaries
Business Acquisition [Line Items]
Business acquisition, number of treasury shares issued (in shares)	925,264
Consideration transferred \| $	$ 72.0
Number of customers \| customer	10,100