Earnings per Common Share

Basic earnings per common share is calculated by dividing net income attributable to common shareholders by the weighted-average number of common shares outstanding during the period excluding the weighted-average number of unvested restricted shares outstanding during the period. Diluted earnings per common share is calculated by dividing net income attributable to common shareholders by the weighted-average number of common shares outstanding during the period, plus any shares that could potentially be outstanding during the period. The potential shares consist of the unvested restricted share grants and unvested performance units, calculated using the treasury stock method. Any anti-dilutive shares have been excluded from the diluted earnings per share calculation.

Unvested share-based payment awards that contain non-forfeitable rights to dividends or dividend equivalents (whether paid or unpaid) are participating shares and are considered in the computation of earnings per share pursuant to the two-class method. If there were any undistributed earnings allocable to participating shares, they would be deducted from net income attributable to common shareholders used in the basic and diluted earnings per share calculations.

For the three months ended June 30, 2016, approximately $0.1 million represented the undistributed earnings that were allocable to participating shares. For the six months ended June 30, 2016, there was an insignificant amount of undistributed earnings that were allocable to participating shares. For the three and six months ended June 30, 2015, approximately $0.1 million and $0.1 million, respectively, represented the undistributed earnings that were allocable to participating shares.

The limited partners’ outstanding limited partnership units in the Operating Partnership (which may be redeemed for common shares of beneficial interest under certain circumstances) have been excluded from the diluted earnings per share calculation as there was no effect on the amounts for the three and six months ended June 30, 2016 and 2015, since the limited partners’ share of income would also be added back to net income attributable to common shareholders.

The computation of basic and diluted earnings per common share is as follows (in thousands, except share and per share data):



	For the three months ended June 30,						For the six months ended June 30,
	2016			2015			2016			2015
Numerator:
Net income attributable to common shareholders	$	58,447		$	55,991		$	83,744		$	103,841
Less: Dividends paid on unvested restricted shares	(274		)	(238		)	(687		)	(518		)
Less: Undistributed earnings attributable to unvested restricted shares	(117		)	(72		)	(10		)	(95		)
Net income attributable to common shareholders excluding amounts attributable to unvested restricted shares	$	58,056		$	55,681		$	83,047		$	103,228

Denominator:
Weighted-average number of common shares - basic	123,544,034			130,670,629			123,641,928			130,969,957
Unvested restricted shares	373,039			188,138			387,755			232,682
Unvested performance units	25,773			759,926			22,273			745,293
Weighted-average number of common shares - diluted	123,942,846			131,618,693			124,051,956			131,947,932

Net income per share attributable to common shareholders - basic	$	0.47		$	0.43		$	0.67		$	0.79

Net income per share attributable to common shareholders - diluted	$	0.47		$	0.42		$	0.67		$	0.78