Income Per Share of Common Stock (Tables)

3 Months Ended

Mar. 31, 2018

Earnings Per Share [Abstract]

Summary of Reconciliation of Numerator and Denominator Used to Calculate Basic and Diluted Income (Loss) Per Share of Common Stock

A reconciliation of the numerator and denominator used to calculate basic and diluted income per share of common stock ("EPS") is presented in the following table:

	Three months ended March 31,
	2018			2017
	(In millions, except per share amounts)
Numerator:
Net income	$	14.0		$	5.9
Income allocated to participating securities	(0.3		)	(0.1		)
Net income for basic and diluted earnings per share	$	13.7		$	5.8
Denominator:
Basic weighted average shares	73.7			72.3
Effect of:
2.25% Convertible Senior Notes ("2 1/4% Notes") (1)	0.9			—
Employee stock options and stock purchase plan (2)	0.1			—
Diluted weighted average shares	74.7			72.3
Basic
Basic net income per share	$	0.19		$	0.08
Diluted
Diluted net income per share	$	0.18		$	0.08

_______

(1) The Company's 2 ¹/₄% Notes were not included in the computation of diluted EPS for the three months ended March 31, 2017, because the average market price of the common stock did not exceed the conversion price and the Company only expects the conversion premium for the 2 ¹/₄% Notes to be settled in common shares.

(2) There was less than 0.1 million of common share dilution impact from employee stock options and the stock purchase plan for the three months ended March 31, 2017.

Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share

The following table sets forth the potentially dilutive security excluded from the computation because its effect would have been anti-dilutive:

	Three months ended March 31,
	2018	2017
	(In millions)
4 1/16% Convertible Subordinated Debentures	—	0.3