3. Share Data

Basic earnings per share are computed using net income attributable to common shareholders and the weighted average number of common shares outstanding. Diluted earnings per share reflect common shares issuable from the assumed conversion of common share options and share awards granted and units convertible into common shares. Only those items having a dilutive impact on our basic earnings per share are included in diluted earnings per share. Our unvested share-based awards are considered participating securities and are reflected in the calculation of basic and diluted earnings per share using the two-class method. The number of common share equivalent securities excluded from the diluted earnings per share calculation was approximately 2.1 million, 2.3 million, and 4.0 million for the years ended December 31, 2013, 2012, and 2011, respectively. These securities, which include common share options and share awards granted and units convertible into common shares, were excluded from the diluted earnings per share calculation as they are anti-dilutive.

The following table presents information necessary to calculate basic and diluted earnings per share for the periods indicated:



	Year Ended December 31,
(in thousands, except per share amounts)	2013			2012			2011
Earnings per share calculation – basic
Income from continuing operations attributable to common shareholders	$	151,594		$	154,116		$	7,383
Amount allocated to participating securities	(3,177		)	(2,784		)	(551		)
Income from continuing operations attributable to common shareholders, net of amount allocated to participating securities	$	148,417		$	151,332		$	6,832
Income from discontinued operations, including gain on sale, attributable to common shareholders	184,770			129,274			41,996
Net income attributable to common shareholders, as adjusted	$	333,187		$	280,606		$	48,828

Income from continuing operations attributable to common shareholders,as adjusted – per share	$	1.70		$	1.81		$	0.09
Income from discontinued operations, including gain on sale, attributable to common shareholders – per share	2.12			1.54			0.58
Net income attributable to common shareholders, as adjusted – per share	$	3.82		$	3.35		$	0.67

Weighted average number of common shares outstanding – basic	87,204			83,772			72,756



	Year Ended December 31,
(in thousands, except per share amounts)	2013		2012		2011
Earnings per share calculation – diluted
Income from continuing operations attributable to common shareholders, net of amount allocated to participating securities	$	148,417	$	151,332	$	6,832
Income allocated to common units from continuing operations	1,133		1,984		—
Income from continuing operations attributable to common shareholders, as adjusted	$	149,550	$	153,316	$	6,832
Income from discontinued operations, including gain on sale, attributable to common shareholders	184,770		129,274		41,996
Net income attributable to common shareholders, as adjusted	$	334,320	$	282,590	$	48,828

Income from continuing operations attributable to common shareholders, as adjusted – per share	$	1.69	$	1.79	$	0.09
Income from discontinued operations, including gain on sale, attributable to common shareholders – per share	2.09		1.51		0.57
Net income attributable to common shareholders, as adjusted – per share	$	3.78	$	3.30	$	0.66

Weighted average number of common shares outstanding – basic	87,204		83,772		72,756
Incremental shares issuable from assumed conversion of:
Common share options and share awards granted	476		647		706
Common units	814		1,137		—
Weighted average number of common shares outstanding – diluted	88,494		85,556		73,462