(11) CAPITAL STOCK

We have authorized capital stock of 485.0 million shares which includes 475.0 million shares of common stock and 10.0 million shares of preferred stock. We currently have no preferred stock issued or outstanding. The following is a schedule of changes in the number of common shares outstanding since the beginning of 2016:

	Nine Months Ended September 30, 2017		Year Ended December 31, 2016
Beginning balance		247,144,356		169,316,460
MRD Merger		—		77,042,749
Restricted stock grants		536,536		490,609
Restricted stock units vested		341,358		266,541
PSU-TSR units settled		85,461		—
Shares retired		—		(739	)
Treasury shares issued		15,580		28,736
Ending balance		248,123,291		247,144,356