Earnings Per Share (Tables)

6 Months Ended

Jun. 30, 2014

Earnings Per Share [Abstract]

Earnings per share

				Six months ended June 30,				Three months ended June 30,
				2014		2013		2014		2013
Net earnings				$	205,047	$	194,012	$	97,136	$	88,162
Less: net earnings attributable to unvested restricted stock					(3,282)		(3,227)		(1,590)		(1,445)
		Net earnings available to common stock		$	201,765	$	190,785	$	95,546	$	86,717
Weighted-average common shares outstanding					98,551		98,965		98,442		98,870
Dilutive effect of outstanding securities (determined using
	treasury stock method)				240		245		218		251
		Weighted-average common shares and potential
			common shares outstanding		98,791		99,210		98,660		99,121
Earnings per common share
		Basic		$	2.05	$	1.93	$	0.97	$	0.88
		Diluted		$	2.04	$	1.92	$	0.97	$	0.87