Earnings Per Share (tables)

3 Months Ended

Mar. 31, 2012

Earnings per share of common stock [Abstract]

EPS Calculation Table Text Block

		Three Months Ended
		March 31,
Thousands, except per share amounts			2012		2011
Net income		$	40,607	$	40,773
Average common shares outstanding - basic			26,781		26,670
	Additional shares for stock-based compensation plans(1)		81		54
Average common shares outstanding - diluted			26,862		26,724
Earnings per share of common stock - basic		$	1.52	$	1.53
Earnings per share of common stock - diluted		$	1.51	$	1.53
(1)Additional shares not included in diluted earnings per share calculation
because of antidilutive impact			1,010		2,150