EARNINGS PER SHARE (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2020	Sep. 30, 2019
Basic EPS Calculation
Net income available for common stock	$ 21,079	$ 25,325	$ 91,677	$ 17,457	$ 24,470	$ 93,660	$ 138,081	$ 135,587
Weighted Average Number of Shares Outstanding, Basic	53,190			52,933			53,084	52,883
Earnings Per Share, Basic	$ 0.40			$ 0.33			$ 2.60	$ 2.56
Diluted EPS Calculation
Net income available for common stock	$ 21,079	$ 25,325	$ 91,677	$ 17,457	$ 24,470	$ 93,660	$ 138,081	$ 135,587
Effect of dilutive securities on income	$ 0			$ 0			$ 0
Effect of dilutive securities on shares	218			334			229	346
Weighted Average Number of Shares Outstanding, Diluted	53,408			53,267			53,313	53,229
Earnings Per Share, Diluted	$ 0.39			$ 0.33			$ 2.59	$ 2.55