Interim Financial Information (Unaudited) (Tables)

12 Months Ended

Dec. 31, 2011

Interim Financial Information (Unaudited)

Interim Financial Information (Unaudited)

	Three months ended
	March 31		June 30			September 30		December 31
	(Thousands, except per share amounts)
2011 (a)
Operating revenues	$	472,695	$	367,791		$362,644		$	436,804
Operating income	220,412		153,170			314,984		172,753
Net income	122,255		87,754			178,914		90,846
Earnings per share of common stock:
Net income
Basic	$          0.82		$		0.59	$	1.20	$	0.61
Diluted	$         0.82		$		0.58	$	1.19	$	0.60
2010 (a)
Operating revenues	$	449,039	$	270,566		$	270,859	$	383,931
Operating income	169,113		78,529			88,182		134,655
Net income	88,065		30,000			36,522		73,113
Earnings per share of common stock:
Net income
Basic	$	0.66	$	0.20		$	0.24	$	0.49
Diluted	$	0.65	$	0.20		$	0.24	$	0.49

(a)The sum of the quarterly data in some cases may not equal the yearly total due to rounding.