Net Income Per Common Share

The following table sets forth the computation of basic and diluted net income per common share (in millions, except per share amounts):



	Three Months Ended
	June 30,
	2018		2017
Net income	$	35.7	$	170.6
Weighted average common shares outstanding	235.2		229.4
Dilutive effect of stock options and RSUs	4.0		4.5
Dilutive effect of 2007 Junior Convertible Debt	—		4.1
Dilutive effect of 2015 Senior Convertible Debt	13.0		4.9
Dilutive effect of 2017 Senior Convertible Debt	—		—
Dilutive effect of 2017 Junior Convertible Debt	—		—
Weighted average common and potential common shares outstanding	252.2		242.9
Basic net income per common share	$	0.15	$	0.74
Diluted net income per common share	$	0.14	$	0.70

The Company computed basic net income per common share using net income and the weighted average number of common shares outstanding during the period. The Company computed diluted net income per common share using net income and the weighted average number of common shares outstanding plus potentially dilutive common shares outstanding during the period.

Potentially dilutive common shares from employee equity incentive plans are determined by applying the treasury stock method to the assumed exercise of outstanding stock options and the assumed vesting of outstanding RSUs. Weighted average common shares exclude the effect of option shares which are not dilutive. There were no anti-dilutive option shares for the three months ended June 30, 2018 and 2017.

Diluted net income per common share for the three months ended June 30, 2018, includes 13.0 million shares issuable upon the exchange of the Company's 2015 Senior Convertible Debt. The Company's 2007 Junior Convertible Debt was fully settled as of December 31, 2017. Diluted net income per common share for the three months ended June 30, 2017 included 4.1 million shares and 4.9 million shares issuable upon the exchange of the Company's 2007 Junior Convertible Debt and 2015 Senior Convertible Debt, respectively (see Note 13 for details on the convertible debt). The convertible debt has no impact on diluted net income per common share unless the average price of the Company's common stock exceeds the conversion price because the principal amount of the debentures will be settled in cash upon conversion. Prior to conversion, the Company will include, in the diluted net income per common share calculation, the effect of the additional shares that may be issued when the Company's common stock price exceeds the conversion price using the treasury stock method. The following is the weighted average conversion price per share used in calculating the dilutive effect (See Note 13 for details on the convertible debt):



	June 30,
	2018		2017
2007 Junior Convertible Debt ⁽¹⁾	$	—	$	23.69
2015 Senior Convertible Debt	$	63.27	$	64.35
2017 Senior Convertible Debt	$	98.67	$	100.35
2017 Junior Convertible Debt	$	96.93	$	98.59

⁽¹⁾No longer outstanding as of December 31, 2017.