Stockholders' Equity

6 Months Ended

Jun. 30, 2018

(7) Stockholders’ Equity

A reconciliation of the number of shares of our common stock follows:

	Six months ended June 30,
	2018			2017
	(In thousands)
Common stock, beginning of period		44,251			45,721
Shares issued for stock options exercised		-			38
Shares of common stock issued upon lapse of restricted stock units ("RSUs")		329			341
Common stock retired		(1,412	)		(1,065	)
Common stock, end of period		43,168			45,035

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, 2018, we had a total of 717,358 RSUs and 85,010 PSUs outstanding. The PSU outstanding balance is based on the target 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 target performance. See Note 9 (Share Based Transactions) for discussion of the PSU award structure.

On February 6, 2018, our Board of Directors authorized a share repurchase program for up to $275.0 million of our outstanding common stock for purchases through June 30, 2019 (the “share repurchase program”). Under the share repurchase program, we repurchased 1,358,480 shares of our common stock in the open market for an aggregate purchase price of $133.7 million through June 30, 2018. Approximately $141.3 million remains available for repurchases of our outstanding common stock under the share repurchase program as of June 30, 2018.