Share-based compensation (Tables)

12 Months Ended

Dec. 31, 2021

Share-based Payment Arrangement [Abstract]

A summary of our restricted share awards from January 1, 2021 to December 31, 2021 is as follows:


	Number of Shares	Weighted-Average Grant Date Fair Value
Unvested balance at January 1, 2021	2,225,139	$	8.53
Granted	1,925,298	5.45
Vested	(1,126,198)	8.68
Forfeited	(17,448)	7.68
Unvested balance at December 31, 2021	3,006,791	$	6.50

Summary of Additional Information on Restricted Share Awards and Performance Share Awards

The following table provides additional information on our restricted share awards for the years ended December 31, 2021, 2020 and 2019 ($ in thousands, except per share data):


	Year Ended December 31,
	2021		2020		2019
Weighted-average grant date fair value	$	5.45	$	7.92	$	7.25
Fair value of vested restricted share awards	$	7,455	$	4,837	$	3,600
Share-based compensation expense	$	10,645	$	9,123	$	8,065

The following table provides additional information on our performance share awards for the years ended December 31, 2021, 2020 and 2019 ($ in thousands, except per share data):


	Year Ended December 31,
	2021		2020		2019
Weighted-average grant date fair value	$	5.18	$	6.38	$	5.83
Share-based compensation expense	$	2,518	$	1,035	$	780

Summary of Key Inputs Used in Monte-Carlo Simulation

The table below summarizes the key inputs used in the Monte-Carlo simulation ($ in thousands):


Performance Award Grant Date	Percentage of Total Award		Grant Date Fair Value by Component		Volatility (1)		Interest Rate (2)		Dividend Yield
January 2, 2019
Total Shareholder Return	50	%	$	537	27.78	%	2.46	%	—	%
Adjusted EBITDA Comparison	50	%	$	900	—	%	—	%	—	%
September 19, 2019
Total Shareholder Return	50	%	$	287	25.86	%	1.72	%	—	%
Adjusted EBITDA Comparison	50	%	$	448	—	%	—	%	—	%
January 2, 2020
Total Shareholder Return	50	%	$	1,334	24.87	%	1.58	%	—	%
Adjusted EBITDA Comparison	50	%	$	2,187	—	%	—	%	—	%
January 4, 2021
Peer Shareholder Return	50	%	$	3,088	57.69	%	0.16	%	—	%
Growth Rate	50	%	$	2,230	57.69	%	0.16	%	—	%

________

(1) Expected volatility was determined based on the historical share prices in our industry.

(2) The risk-free rate was based on U.S. Treasury zero coupon issues with a remaining term equal to the remaining term of the measurement period.

Summary of Performance Share Awards

A summary of our performance share awards from January 1, 2021 to December 31, 2021 is as follows:


	Number of Shares	Weighted-Average Grant Date Fair Value
Unvested balance at January 1, 2021	—	$	—
Granted	1,027,519	5.18


Unvested balance at December 31, 2021	1,027,519	$	5.18