Net Income Per Share (Tables)

6 Months Ended

Jun. 30, 2013

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)	2013			2012			2013			2012
Net income	$	52,007		$	42,471		$	112,138		$	91,904
Net income attributable to unvested awarded performance stock		(1,157	)		(1,248	)		(2,467	)		(2,744	)
Net income attributable to common shares	$	50,850		$	41,223		$	109,671		$	89,160
Weighted average number of common shares outstanding – basic		144,041			143,298			143,984			143,323
Less unvested awarded performance stock included in weighted average number of common shares outstanding – basic		(3,205	)		(4,212	)		(3,168	)		(4,279	)
Weighted average number of common shares outstanding for basic earnings per common share		140,836			139,086			140,816			139,044
Dilutive effect of stock options		2,185			2,742			2,122			2,620
Weighted average number of shares outstanding – diluted		143,021			141,828			142,938			141,664
Net income per share:
Basic	$	0.36		$	0.30		$	0.78		$	0.64
Diluted	$	0.36		$	0.29		$	0.77		$	0.63