Earnings per Share

An economic interest in Partnership common equity is held by the holders of Class B exchangeable limited partnership units (the “Partnership exchangeable units”), which is reflected as a noncontrolling interest in our equity. See Note 11, Shareholders’ Equity.

Basic and diluted earnings per share is computed using the weighted average number of shares outstanding for the period. We apply the treasury stock method to determine the dilutive weighted average common shares represented by Partnership exchangeable units and outstanding equity awards, unless the effect of their inclusion is anti-dilutive. The diluted earnings per share calculation assumes conversion of 100% of the Partnership exchangeable units under the “if converted” method. Accordingly, the numerator is also adjusted to include the earnings allocated to the holders of noncontrolling interests.

The following table summarizes the basic and diluted earnings per share calculations (in millions, except per share amounts):



	Three Months Ended September 30,				Nine Months Ended September 30,
	2018		2017		2018		2017
Numerator:
Net income attributable to common shareholders - basic	$	133.6	$	91.4	$	449.0	$	231.1
Add: Net income attributable to noncontrolling interests	116.1		87.6		393.3		222.2
Net income available to common shareholders and noncontrolling interests - diluted	$	249.7	$	179.0	$	842.3	$	453.3

Denominator:
Weighted average common shares - basic	250.5		236.6		248.6		235.7
Exchange of noncontrolling interests for common shares (Note 11)	217.6		226.8		217.6		226.9
Effect of other dilutive securities	6.8		15.2		8.1		15.1
Weighted average common shares - diluted	474.9		478.6		474.3		477.7

Basic earnings per share	$	0.53	$	0.39	$	1.81	$	0.98
Diluted earnings per share	$	0.53	$	0.37	$	1.78	$	0.95
Anti-dilutive securities outstanding	5.9		3.8		5.9		3.8