	Six months ended June 30,
	2020			2019
	(In thousands)
Common stock, beginning of period	$	41,207		$	42,694
Shares issued for stock options exercised		-			-
Shares of common stock issued upon lapse of restricted stock units (“RSUs”)		239			304
Common stock retired		(1,779	)		(990	)
Common stock, end of period	$	39,667		$	42,008

The above reconciliation excludes RSUs and performance-based stock units (“PSUs”), which do not have voting rights. As sales restrictions on RSUs lapse and PSUs are earned, we issue common shares with voting rights. As of June 30, 2020, we had a total of 327,797 RSUs and 81,796 PSUs outstanding. The PSU outstanding balance is based on the number of PSUs granted pursuant to the award agreements; however, the actual number of common shares issued could be higher or lower based on actual versus targeted performance. See Note 9 (Share-Based Transactions) for discussion of the PSU award structure.

On February 7, 2019, our Board of Directors authorized a share repurchase program for up to $275.0 million of our outstanding common stock through June 30, 2020. On February 10, 2020, our Board of Directors authorized a new share repurchase program for up to $300.0 million of our outstanding common stock (including $50.0 million that remained from the prior repurchase program) for purchases through June 30, 2021. Under these share repurchase programs, we repurchased 1,728,672 shares of our common stock in the open market for an aggregate purchase price of $176.6 million through June 30, 2020. Approximately $123.4 million remains available for repurchases of our outstanding common stock under the share repurchase program as of June 30, 2020.