Earnings Per Share (Tables)

6 Months Ended

Jun. 30, 2014

Earnings Per Share [Abstract]

Computation of Basic and Diluted Earnings per Share

	Three Months Ended				Six Months Ended
	June 30,				June 30,
(in thousands, except per share data)	2014		2013		2014		2013
Net income attributable to common shareholders	$	59,697	$	54,874	$	108,381	$	112,665
Average basic shares outstanding	58,883		57,908		58,682		57,684
Effect of dilutive stock options	960		920		982		910
Average diluted shares outstanding	59,843		58,828		59,664		58,594
Earnings per basic share	$	1.01	$	0.95	$	1.85	$	1.95
Earnings per diluted share	$	1.00	$	0.93	$	1.82	$	1.92