EARNINGS PER COMMON SHARE (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Earnings (loss) per common share
Net income (loss)	$ 120,040	$ 177,043	$ (57,783)	$ 285,828
Less: Preferred share dividends	7,563	10,656	15,125	21,313
Net income (loss) available (attributable) to common shareholders	$ 112,477	$ 166,387	$ (72,908)	$ 264,515
Weighted average common shares outstanding (in shares)	84,303	83,941	84,198	83,834
Earnings (loss) per common share (in usd per share)	$ 1.33	$ 1.98	$ (0.87)	$ 3.16
Earnings (loss) per diluted common share
Net income (loss) available (attributable) to common shareholders	$ 112,477	$ 166,387	$ (72,908)	$ 264,515
Weighted average common shares outstanding (in shares)	84,303	83,941	84,198	83,834
Share-based compensation plans (in shares)	297	460	0	504
Weighted average diluted common shares outstanding (in shares)	84,600	84,401	84,198	84,338
Earnings (loss) per diluted common share (in usd per share)	$ 1.33	$ 1.97	$ (0.87)	$ 3.14
Weighted average anti-dilutive shares excluded from the dilutive computation (in shares)	1,391	3	1,098	302