EARNINGS PER SHARE - Components of Basic and Diluted EPS (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Earnings Per Share [Abstract]
Net Income Attributable to Common Shareholders	$ 250,000	$ 318,900	$ 31,500	$ 308,700	$ 231,300	$ 289,400	$ 242,800	$ 269,500	$ 909,053	$ 1,033,000	$ 987,996
Weighted Average Common Shares Outstanding:
Basic (in shares)									321,416,086	317,370,369	317,411,097
Dilutive Effect of:
Share-Based Compensation Awards and Other (in shares)									762,215	623,565	620,483
Equity Forward Sale Agreement (in shares)									763,335	0	0
Dilutive Effect (in shares)									1,525,550	623,565	620,483
Diluted (in shares)									322,941,636	317,993,934	318,031,580
Basic EPS (in dollars per share)	$ 0.77	$ 0.98	$ 0.10	$ 0.97	$ 0.73	$ 0.91	$ 0.76	$ 0.85	$ 2.83	$ 3.25	$ 3.11
Diluted EPS (in dollars per share)	$ 0.76	$ 0.98	$ 0.10	$ 0.97	$ 0.73	$ 0.91	$ 0.76	$ 0.85	$ 2.81	$ 3.25	$ 3.11