STOCK BASED AND DEFERRED COMPENSATION (Tables)

12 Months Ended

Dec. 31, 2020

Share-based Payment Arrangement [Abstract]

Summary of Nonvested (Restricted) Shares and Units Activity

We grant time-based and performance-based restricted shares or units. Performance-based restricted shares are only granted to executive officers. All performance shares only vest upon the attainment of certain financial and operational criteria as established and approved by our Board of Directors. The number of shares that may be issued to the award recipients may be greater or lesser than the target award amount depending on actual performance achieved as compared to the performance targets set forth in the awards.


	Nonvested Restricted Share Activity (time-based)	Weighted Average Grant Date Fair Value		Nonvested Restricted Share Activity (performance- based)	Weighted Average Grant Date Fair Value
Outstanding at January 1, 2018	982,652	$	35.59	287,005	$	35.80
Granted	315,247	46.07		157,637	45.20
Vested (Earned/Released)	(288,709)	37.93		(36,801)	41.17
Forfeited (1)	(85,900)	37.53		(29,386)	41.17
Outstanding as of December 31, 2018	923,290	38.25		378,455	38.77
Granted (2)	385,328	44.46		115,191	40.46
Vested (Earned/Released)	(347,555)	37.15		(87,737)	34.39
Forfeited (1)	(126,443)	40.45		—	—
Outstanding at December 31, 2019	834,620	41.25		405,909	40.20
Granted (3)	225,593	72.51		80,193	61.06
Vested (Earned/Released)	(234,842)	38.80		(178,174)	34.10
Forfeited (1)	(34,754)	46.31		—	—
Outstanding at December 31, 2020	790,617	$	50.67	307,928	$	49.16

(1)Forfeitures on time-based nonvested shares are a result of terminations of employment, while forfeitures on performance-based nonvested shares are a result of failing to attain certain goals as outlined in our executive officers' compensation agreements.

(2)Performance-based shares granted for the year ended December 31, 2019 includes 21,039 shares that were issued as a result of the performance achievement exceeding the performance targets related to grants to our executive officers for the year ended December 31, 2016. These shares vested in March 2019.

(3)Performance-based shares granted for the year ended December 31, 2020 includes 24,054 shares that were issued as a result of the performance achievement exceeding the performance targets related to grants to our executive officers for the year ended December 31, 2017. These shares vested in February 2020.

Summary of Compensation Expense and Stock Award Activity

Below is a summary of compensation expense and stock award activity (in thousands):


	Years Ended December 31,
	2020		2019		2018
Stock-based compensation expense	$	19,995	$	19,607	$	17,170

Summary of Additional Information Regarding Stock Plan

The following table includes additional information regarding our Plan (dollars in thousands):


	At December 31,
	2020		2019
Unrecognized stock-based compensation cost	$	22,687	$	22,341
Weighted average years expense recognition period	2.01		1.70
Total equity awards outstanding (1)	1,098,545		1,240,529

(1) Includes unvested restricted stock, performance-based awards (assuming 100% payout) and restricted stock units.