Earnings Per Share (Tables)

6 Months Ended

Jun. 30, 2012

Earnings Per Share [Abstract]

Earnings per share basic and diluted

	Three Months Ended June 30,						Six Months Ended June 30,
	2012			2011			2012			2011
	(in thousands, except per share data)
Income (numerator):
Basic:
Net income	$	30,547		$	57,196		$	81,521		$	96,988
Net income attributable to participating securities		(742	)		(1,192	)		(1,982	)		(2,022	)
Net income attributable to common stock - basic	$	29,805		$	56,004		$	79,539		$	94,966
Diluted:
Net income	$	30,547		$	57,196		$	81,521		$	96,988
Net income attributable to participating securities		(742	)		(1,191	)		(1,980	)		(2,021	)
Net income attributable to common stock - diluted	$	29,805		$	56,005		$	79,541		$	94,967
Weighted average shares (denominator):
Weighted average shares - basic		48,303			47,961			48,279			47,930
Diluted effect of stock options		41			45			43			43
Weighted average shares - diluted		48,344			48,006			48,322			47,973
Basic income per common share	$	0.62		$	1.17		$	1.65		$	1.98
Diluted income per common share	$	0.62		$	1.17		$	1.65		$	1.98