Net Income Per Share (Tables)

6 Months Ended

Jun. 30, 2015

Earnings Per Share [Abstract]

Reconciliation between Basic and Diluted Weighted Average Shares Outstanding

The following is a reconciliation between basic and diluted weighted average shares outstanding:

	For the three months   ended June 30,						For the six months   ended June 30,
(in thousands, except per share data)	2015			2014			2015			2014
Net income	$	61,005		$	61,755		$	117,956		$	114,170
Net income attributable to unvested awarded performance stock	(1,439		)	(1,531		)	(2,802		)	(2,915		)
Net income attributable to common shares	$	59,566		$	60,224		$	115,154		$	111,255
Weighted average number of common shares outstanding – basic	140,839			144,840			141,803			145,133
Less unvested awarded performance stock included in weighted average number of common shares outstanding – basic	(3,321		)	(3,590		)	(3,369		)	(3,705		)
Weighted average number of common shares outstanding for basic earnings per common share	137,518			141,250			138,434			141,428
Dilutive effect of stock options	2,310			1,782			2,213			1,741
Weighted average number of shares outstanding – diluted	139,828			143,032			140,647			143,169
Net income per share:
Basic	$	0.43		$	0.43		$	0.83		$	0.79
Diluted	$	0.43		$	0.42		$	0.82		$	0.78