Correction of Prior Period Financial Statement (Tables)

12 Months Ended

Dec. 31, 2011

Correction of Prior Period Financial Statement [Abstract]

Summary of the effects of the correction of errors on the Consolidated Balance Sheet

	As of December 31, 2010
in thousands	As Reported		Correction			As Restated
Balance Sheet
Assets
Current deferred income taxes		$53,794		$910			$54,704
Prepaid expenses		19,374		735			20,109
Total current assets		772,106		1,645			773,751
Total assets		$8,337,891		$ 1,645			$8,339,536
Liabilities
Other accrued liabilities		$112,408		$16,676			$129,084
Total current liabilities		565,672		16,676			582,348
Noncurrent deferred income taxes		849,448		(5,849	)		843,599
Total liabilities		$4,372,911		$10,827			$4,383,738
Equity
Retained earnings		$1,512,863		($9,182	)		$1,503,681
Total equity		3,964,980		(9,182	)		3,955,798
Total liabilities and equity		$8,337,891		$1,645			$8,339,536