Quarterly Operations (Unaudited) (Tables)

12 Months Ended

Dec. 31, 2011

Notes to Financial Statements [Abstract]

Schedule of Quarterly Financial Information [Table Text Block]

		Quarters Ended
		March 31		June 30		September 30		December 31
		(In thousands, except per share amounts)
Operating revenues		$	746,822	$	631,607	$	617,211	$	670,314
Operating income			108,032		115,022		110,526		144,278
Net earnings			60,662		59,773		58,032		76,957
Net earnings available for common
	stockholders		60,662		59,773		58,032		76,957
Basic earnings per share:		$	0.49	$	0.48	$	0.47	$	0.62
Dilutive earnings per share:		$	0.48	$	0.47	$	0.46	$	0.61
The following table presents the operating results for each quarter of the year ended December 31, 2010.
		Quarters Ended
		March 31		June 30		September 30		December 31
		(In thousands, except per share amounts)
Operating revenues		$	758,994	$	573,096	$	487,527	$	670,296
Operating income			119,278		131,744		76,407		133,186
Net earnings from continuing operations			56,460		74,889		37,331		73,968
Loss from discontinued operations			-		-		-		(18,100)
Net earnings available for common
	stockholders		54,289		69,424		36,632		55,868
Basic earnings per share:
	Continuing operations	$	0.44	$	0.56	$	0.29	$	0.59
	Available for common stockholders	$	0.43	$	0.55	$	0.29	$	0.45
Dilutive earnings per share:
	Continuing operations	$	0.44	$	0.56	$	0.29	$	0.59
	Available for common stockholders	$	0.43	$	0.55	$	0.29	$	0.45