Earnings Per Share

12 Months Ended

Dec. 31, 2019

Basic earnings per share is calculated by dividing net income attributable to controlling interests by the weighted average number of shares of common stock outstanding. Diluted earnings per share is similar to basic earnings per share, but is adjusted for the effect of potentially issuable common stock, except when inclusion is antidilutive.

The calculation of basic and diluted earnings per share of common stock for the years ended December 31, 2019, 2018 and 2017 is as follows (dollars in millions, except per share data):



	2019			2018			2017
Numerator:
Net income attributable to controlling interests	$	223.9		$	136.4		$	4.2
Less: Total income available to participating unvested securities⁽¹⁾	(0.1		)	(0.4		)	(0.2		)
Total net income attributable to common stock	$	223.8		$	136.0		$	4.0
Denominator:
Weighted-average shares of common stock outstanding—basic	91,205,412			107,431,821			110,708,598
Potential shares of common stock
Restricted stock units	63,540			191,371			672,544
Weighted-average shares of common stock outstanding—diluted	91,268,952			107,623,192			111,381,142
Earnings per share of common stock attributable to controlling interests:
Basic	$	2.45		$	1.27		$	0.04
Diluted	$	2.45		$	1.26		$	0.04


(1)	Income available to participating unvested securities includes dividends paid on unvested restricted shares and their proportionate share of undistributed earnings.

Employee options to purchase 8,970,000 and 6,900,000 shares were not included in the computation of diluted EPS for the year ended December 31, 2019 and 2018 because the assumed proceeds from exercising such options exceed the average price of the common stock for the period and, therefore, the options are deemed antidilutive.