At March 31, 2023 and December 31, 2022, 2,634,034 and 2,896,604 shares of common stock, respectively, were available for grant under our Incentive Plan. The unamortized compensation cost of awards issued under the Incentive Plan, which are settled by delivery of shares of common stock and purchases under the Employee Stock Purchase Plan, totaled $42 million at March 31, 2023, as shown in the following table.


	Three Months Ended March 31, 2023
(In Thousands)	Restricted Stock Units		Deferred Stock Units		Performance Stock Units		Employee Stock Purchase Plan		Total
Unrecognized compensation cost at beginning of period	$	5,068	$	19,849	$	15,271	$	—	$	40,188
Equity grants	1,982		5,950		—		422		8,354

Equity grant forfeitures	(174)		—		—		—		(174)
Equity compensation expense	(1,420)		(2,930)		(1,734)		(106)		(6,190)
Unrecognized Compensation Cost at End of Period	$	5,456	$	22,869	$	13,537	$	316	$	42,178

At March 31, 2023, the weighted average amortization period remaining for all of our equity awards was less than two years.

At March 31, 2023 and December 31, 2022, there were 703,499 and 806,119 RSUs outstanding, respectively. During the three months ended March 31, 2023, there were 249,598 RSUs granted, 336,959 RSUs distributed, and 15,259 RSUs forfeited. Unvested RSUs at March 31, 2023 vest through 2027.

At March 31, 2023 and December 31, 2022, there were 5,350,399 and 4,831,338 DSUs outstanding, respectively, of which 2,741,004 and 2,495,787, respectively, had vested. During the three months ended March 31, 2023, there were 746,592 DSUs granted, 227,531 DSUs distributed, and zero DSUs forfeited. Unvested DSUs at March 31, 2023 vest through 2027.

At March 31, 2023 and December 31, 2022, the target number of PSUs that were unvested was 2,078,171 and 2,354,002, respectively. Vesting for PSUs generally occurs three years from their respective grant dates based on various total shareholder return performance calculations, as discussed in Note 19 to the Consolidated Financial Statements included in our Annual Report on Form 10-K for the year ended December 31, 2022.

For 275,831 target PSU awards that were granted in December 2019, the performance vesting period ended on January 1, 2023. These 2019 PSU awards failed to reach a threshold level under their performance-based vesting criteria and resulted in the vesting of no shares of our common stock underlying these PSUs.

The ESPP allows a maximum of 850,000 shares of common stock to be purchased in aggregate for all employees. As of March 31, 2023 and December 31, 2022, 686,251 and 657,777 shares had been purchased, respectively, and there remained a negligible amount of uninvested employee contributions in the ESPP at March 31, 2023.