Net Income Per Share

Basic net income per share is computed by dividing net income by the weighted-average number of common shares outstanding, while diluted net income per share is computed by dividing net income attributable to common shareholders by the sum of the weighted-average number of common shares outstanding and the weighted-average number of dilutive potential common shares. Dilutive potential common shares relate to our share-based compensation arrangements and our outstanding convertible senior notes.

The calculation of basic and diluted net income per share was as follows:



	Three Months Ended March 31,
(In thousands, except per-share amounts)	2018		2017
Net income—basic	$	114,486	$	76,472
Adjustment for dilutive Convertible Senior Notes due 2019, net of tax (1)	—		(215		)
Net income—diluted	$	114,486	$	76,257

Average common shares outstanding—basic	215,967		214,925
Dilutive effect of Convertible Senior Notes due 2017	—		701
Dilutive effect of Convertible Senior Notes due 2019	—		1,854
Dilutive effect of share-based compensation arrangements (2)	3,916		4,017
Adjusted average common shares outstanding—diluted	219,883		221,497

Net income per share:

Basic	$	0.53	$	0.36

Diluted	$	0.52	$	0.34

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(1)

As applicable, includes coupon interest, amortization of discount and fees, and other changes in income that would result from the assumed conversion. Included in the three months ended March 31, 2017 is a benefit related to our adjustment of estimated accrued expense to actual amounts, resulting from the January 2017 settlement of our obligations on the remaining Convertible Senior Notes due 2019.


(2)	The following number of shares of our common stock equivalents issued under our share-based compensation arrangements were not included in the calculation of diluted net income per share because they were anti-dilutive:



	Three Months Ended March 31,
(In thousands)	2018	2017
Shares of common stock equivalents	170	445