EARNINGS PER SHARE (Tables)

9 Months Ended

Sep. 30, 2020

Earnings Per Share [Abstract]

Reconciliation of Basic and Diluted Earnings Per Share

The reconciliation of basic and diluted earnings per share for the three and nine months ended September 30, 2020 and 2019 is as follows:

​	Three Months Ended
​	September 30, 2020				September 30, 2019
​	Diluted		Basic		Diluted		Basic
Consolidated operations	​		​		​		​
Income available to common stockholders	$	63,716	$	63,716	$	56,750	$	56,750
Average equivalent shares	​		​		​		​
Shares of common stock	64,562		64,562		64,010		64,010
Effect of dilutive stock-based compensation	​		​		​		​
Stock options	1,809		—		2,367		—
Restricted stock	551		—		325		—
Total average equivalent shares	66,922		64,562		66,702		64,010
Net income per share	$	0.95	$	0.99	$	0.85	$	0.89

​	Nine Months Ended
​	September 30, 2020				September 30, 2019
​	Diluted		Basic		Diluted		Basic
Consolidated operations	​		​		​		​
Income available to common stockholders	$	160,808	$	160,808	$	193,669	$	193,669
Average equivalent shares	​		​		​		​
Shares of common stock	64,278		64,278		63,485		63,485
Effect of dilutive stock-based compensation	​		​		​		​
Stock options	1,770		—		2,425		—
Restricted stock	435		—		253		—
Total average equivalent shares	66,483		64,278		66,163		63,485
Net income per share	$	2.42	$	2.50	$	2.93	$	3.05