Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2014

Accounting Policies [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)	2014			2013			2012
Net income	$	206,896		$	217,112		$	184,045
Net income attributable to unvested awarded performance stock		(5,186	)		(5,446	)		(5,313	)
Net income attributable to common shares	$	201,710		$	211,666		$	178,732
Weighted average basic number of common shares outstanding		144,568			144,662			143,507
Less unvested awarded performance stock included in weighted average basic share outstanding		(3,624	)		(3,629	)		(4,143	)
Weighted average number of common shares outstanding for basic earnings per common share		140,944			141,033			139,364
Dilutive effect of stock options		1,947			1,591			2,646
Weighted average number of shares outstanding		142,891			142,624			142,010
Net income per share:
Basic	$	1.43		$	1.50		$	1.28
Diluted	$	1.41		$	1.48		$	1.26