	Quarter Ended June 30,					Six Months Ended June 30,
(In millions, except per share data)	2020			2019		2020		2019
Basic net income (loss) per common share:
Net income (loss)	$	(1.0	)	$	80.9	$	41.4	$	153.1
Weighted average common shares outstanding		83.7			85.2		83.7		85.1

Basic net income (loss) per common share	$	(0.01	)	$	0.95	$	0.49	$	1.80

Diluted net income (loss) per common share:
Net income (loss)		(1.0	)		80.9		41.4		153.1

Weighted average common shares outstanding — Basic		83.7			85.2		83.7		85.1
Plus incremental shares from assumed conversions:
Restricted stock units		—			0.4		0.2		0.4
Stock options		—			0.6		0.2		0.6
Weighted average common shares outstanding — Dilutive (1)		83.7			86.2		84.1		86.1

Diluted net (loss) income per common share (1)	$	(0.01	)	$	0.94	$	0.49	$	1.78

Total shares underlying stock options of 0.8 million, were excluded from the computation of diluted net income per share for the six months ended June 30, 2020, as they were anti-dilutive. Total shares underlying stock options of 0.1 million and 0.2 million, respectively, were excluded from the computation of diluted net income per share for the three and six months ended June 30, 2019, as they were anti-dilutive.

On April 6, 2020, the Company declared a dividend of one preferred share purchase right (a “right”) for each outstanding share of the Company’s common stock and adopted a stockholder rights plan, as set forth in the rights agreement entered into as of April 6, 2020, between the Company and American Stock Transfer & Trust Company, LLC, as rights agent. The dividend was payable on April 16, 2020 to stockholders of record of the Company’s common stock on such date. In general, the rights plan works by imposing a significant penalty upon any person or group which acquires 15% or more of the outstanding common stock without the prior approval of the board. If the rights become exercisable, each right will allow its holder to purchase from the Company one one-hundredth of a share of Series A Junior Participating Preferred Stock for $150.00. This portion of a preferred share will give the stockholder approximately the same dividend, voting and liquidation rights as would one share of common stock. The rights will not be exercisable until ten days after the public announcement that a person or group has become an “acquiring person” (as defined in the rights agreement) by obtaining beneficial ownership of 15% or more of our outstanding common stock. Prior to exercise, the right does not give its holder any dividend, voting, or liquidation rights. The rights will expire on April 6, 2021. The rights were not exercisable at anytime through June 30, 2020.