Net Income Per Share (Tables)

12 Months Ended

Dec. 31, 2016

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 years ended December 31:

(in thousands, except per share data)	2016			2015			2014
Net income	$	257,491		$	243,318		$	206,896
Net income attributable to unvested awarded performance stock	(6,705		)	(5,695		)	(5,186		)
Net income attributable to common shares	$	250,786		$	237,623		$	201,710
Weighted-average number of common shares outstanding – basic	139,779			141,113			144,568
Less unvested awarded performance stock included in weighted-average number of common shares outstanding – basic	(3,640		)	(3,303		)	(3,624		)
Weighted-average number of common shares outstanding for basic earnings per common share	136,139			137,810			140,944
Dilutive effect of stock options	1,665			2,302			1,947
Weighted-average number of shares outstanding – diluted	137,804			140,112			142,891
Net income per share:
Basic	$	1.84		$	1.72		$	1.43
Diluted	$	1.82		$	1.70		$	1.41