COMMON SHARES - Narrative (Details) - USD ($) $ / shares in Units, $ in Thousands							1 Months Ended		4 Months Ended	7 Months Ended	12 Months Ended
	Dec. 01, 2021	Apr. 08, 2021	Jun. 15, 2020	Mar. 26, 2020	Mar. 23, 2020	Dec. 30, 2019	Mar. 31, 2020	Jun. 30, 2019	Jun. 30, 2020	Dec. 31, 2019	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Equity [Abstract]
Equity offering (in shares)			6,000,000					5,980,000
Price per share (in dollars per share)			$ 86.26
Net proceeds from common shares issued directly by the Company			$ 509,200	$ 314,100	$ 105,700				$ 929,000	$ 852,300	$ 0	$ 928,992	$ 852,254
Common shares issuable pursuant to forward sale agreement (in shares)			11,960,000	4,460,000	1,500,000								6,000,000
Forward sale price (in dollars per share)						$ 71.48
Common shares issued directly by the Company (in shares)							5,960,000
Treasury stock (in shares)											13,415,206	14,864,379
Common stock outstanding (in shares)											344,403,196	342,954,023
Issuance of Treasury Shares for Acquisition of New England Service Company	$ 38,100	$ 38,051
Common Shares
Equity [Abstract]
Common shares issued directly by the Company (in shares)												11,960,000	11,980,000
Common stock outstanding (in shares)										329,880,645	344,403,196	342,954,023	329,880,645	316,885,808
Class of Stock [Line Items]
Issuance of Treasury Shares for Acquisition of New England Service Company (in shares)	462,517