The Company has outstanding common stock and equity awards that consist of RSUs, PSUs and stock options. The RSUs maintain non-forfeitable dividend rights that result in dividend payment obligations on a one-to-one ratio with common shares for any future dividend declarations.

Unvested RSUs are deemed participating securities for purposes of calculating EPS as they maintain dividend rights. We calculate EPS using the two-class method. Under the two-class method, we allocate earnings to common shares and vested RSUs outstanding for the period. Earnings attributable to unvested participating securities, along with the corresponding share counts, are excluded from EPS as reflected in our consolidated statements of income.

In calculating basic EPS, we deduct from net income any dividends and undistributed earnings allocated to unvested RSUs and then divide the result by the weighted-average number of common shares and vested RSUs outstanding for the period.

We determine the potential dilutive effect of PSUs and stock options outstanding (“contingently-issuable shares”) on EPS using the treasury-stock method. Under this method, we determine the proceeds that would be received from the issuance of the contingently- issuable shares if the end of the reporting period were the end of the contingency period. The proceeds from the contingently-issuable shares include: the remaining unrecognized compensation expense of the awards, and the cash received for the exercise price on stock options. We then use the average market price of our common shares during the period the contingently-issuable shares were outstanding to determine how many shares we could repurchase with the proceeds raised from the issuance of the contingently-issuable shares. The net incremental share count issued represents the potential dilutive securities. We then reallocate earnings to common shares and vested RSUs by incorporating the increased fully-diluted share count to determine diluted EPS.

		Year ended December 31,
		2018			2017			2016
	(In thousands, except per-share amounts)
Basic EPS:
Numerator:
Net income		$	324,094		$	350,255		$	219,414
Income attributable to unvested participating securities			(1,893	)		(2,526	)		(1,835	)
Net income used in calculating basic EPS		$	322,201		$	347,729		$	217,579
Denominator:
Weighted-average vested shares			43,854			45,598			47,411
Basic EPS		$	7.35		$	7.63		$	4.59

Diluted EPS:
Numerator:
Net income		$	324,094		$	350,255		$	219,414
Income attributable to unvested participating securities			(1,888	)		(2,521	)		(1,833	)
Net income used in calculating diluted EPS		$	322,206		$	347,734		$	217,581
Denominator:
Weighted-average vested shares			43,854			45,598			47,411
Dilutive effect of incremental shares to be issued for contingently-issuable shares			131			91			42
Weighted-average shares used in calculating diluted EPS			43,985			45,689			47,453
Diluted EPS		$	7.33		$	7.61		$	4.59