Calculation of Earnings per Share

The following table presents the computation of weighted-average shares used in the calculation of basic and diluted earnings per share:



	Three Months Ended June 30,		Six Months Ended June 30,
	2018	2017	2018	2017
	(In thousands)
Weighted-average shares of common stock outstanding	113,936	101,060	105,639	101,759
Weighted-average potential shares of common stock outstanding:
Conversion spread related to Subordinated Convertible Debentures	8,776	22,530	17,178	21,929
Unvested RSUs and ESPP	488	390	582	530
Shares used to compute diluted earnings per share	123,200	123,980	123,399	124,218

The weighted average shares of common stock outstanding for the three and six months ended June 30, 2018, reflects the issuance of 26.1 million shares of common stock related to the settlement of the Subordinated Convertible Debentures on May 1, 2018. The dilutive impact of the conversion spread related to the Subordinated Convertible Debentures is included in the calculation for the three and six months ended June 30, 2018, on a weighted-average basis for the period prior to conversion.

The calculation of diluted weighted average shares outstanding, excludes potentially dilutive securities, the effect of which would have been anti-dilutive, as well as performance-based RSUs granted by the Company for which the relevant performance criteria have not been achieved. The number of potential shares excluded from the calculation was not significant in any period presented.