Stock-Based Compensation Plans (Tables)

12 Months Ended

Dec. 31, 2021

Share-based Payment Arrangement [Abstract]

Summary of stock-based compensation expense, net of amounts capitalized

The following summarizes stock-based compensation expense, net of amounts capitalized to development projects, for the years ended December 31:

thousands	2021		2020		2019
Stock Options (a)(b)	$	227	$	(1,892)	$	1,411
Restricted Stock (c)(d)	7,332		6,520		16,682
Pre-tax stock-based compensation expense	$	7,559	$	4,628	$	18,093
Income tax benefit	$	882	$	167	$	3,699

(a)Amounts shown are net of $0.1 million capitalized to development projects in 2021, $0.2 million capitalized to development projects in 2020 and $0.4 million capitalized to development projects in 2019.

(b)The credit position for the year ended December 31, 2020, was due to significant forfeitures which exceeded the expense.

(c)Amounts shown are net of $2.2 million capitalized to development projects in 2021, $0.9 million capitalized to development projects in 2020 and $1.0 million capitalized to development projects in 2019.

(d)The higher compensation expense for the year ended December 31, 2019, was generally in connection with the Company’s restructuring in 2019.

Summary of stock option plan activity

The following table summarizes stock option activity:

	Stock Options	Weighted-average Exercise Price		Weighted-average Remaining Contractual Term (years)	Aggregate Intrinsic Value
Stock options outstanding at December 31, 2020	372,736	$	100.49
Granted	6,000	$	100.74
Exercised (a)	(82,225)	59.17
Forfeited	(25,000)	104.81
Expired	(1,024)	111.35
Stock options outstanding at December 31, 2021	270,487	$	112.61	4.9	$	1,196,041
Stock options vested and expected to vest at December 31, 2021	268,289	$	112.80	4.9	$	1,156,748
Stock options exercisable at December 31, 2021	182,750	$	117.56	3.6	$	172,806

(a)The total intrinsic value of stock options exercised was $2.6 million during 2021, $2.4 million during 2020, and $2.4 million during 2019, based on the difference between the market price at the exercise date and the exercise price.

Summary of significant assumptions used in Black-Scholes option-pricing model

The fair value on the grant date and the significant assumptions used in the Black‑Scholes option‑pricing model are as follows:

	2021			2020			2019
Weighted-average grant date fair value	$	41.52		$	32.10		$	32.51
Assumptions
Expected life of options (in years)	7.5			7.5			7.5
Risk-free interest rate	1.2		%	0.7		%	2.2		%
Expected volatility	36.5		%	40.4		%	22.6		%
Expected annual dividend per share	—			—			—

Schedule of restricted stock activity

The following table summarizes restricted stock activity:

	Restricted Stock	Weighted-average Grant Date Fair Value
Restricted stock outstanding at December 31, 2020	409,110	$	69.21
Granted	102,410	83.91
Vested	(67,673)	85.39
Forfeited	(37,881)	47.98
Restricted stock outstanding at December 31, 2021	405,966	$	72.20