Comprehensive Income (Components Of Comprehensive Income) (Details) (USD $) In Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Comprehensive Income
Net income	$ 41,777	$ 93,320	$ 118,562	$ 150,544
Amortization of unfunded employee benefit obligations	951	894	2,853	2,683
Amortization of net gain on treasury locks	(282)	(282)	(845)	(1,025)
Amortization of net loss on foreign currency exchange contracts	(1)		(1)
Unrealized losses on treasury locks	(25,455)	(11,101)	(19,935)	(19,374)
Unrealized gains (losses) on foreign currency exchange contracts	(13)	370	189	(555)
Comprehensive income	$ 16,977	$ 83,201	$ 100,823	$ 132,273

The adjustment out of other comprehensive income for accumulated gains and losses from foreign currency exchange contract derivatives designated and qualifying as the effective portion of cash flow hedges that were realized in net income during the period, net of tax.

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- Definition

The adjustment out of other comprehensive income for prior service costs and net loss recognized as a component of net periodic benefit cost during the period, after tax.

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- Definition

The adjustment out of other comprehensive income for accumulated gains and losses from interest rate derivative instrument designated and qualifying as the effective portion of cash flow hedges that were realized in net income during the period, after tax.

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- Definition

Change in accumulated unrealized gains and losses from foreign currency derivative instruments designated and qualifying as the effective portion of cash flow hedges, net of tax effect.

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- Definition

Change in accumulated unrealized gains and losses from interest rate derivative instruments designated and qualifying as the effective portion of cash flow hedges, net of tax effect.

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- Definition

The change in equity [net assets] of a business enterprise during a period from transactions and other events and circumstances from non-owner sources which are attributable to the reporting entity. It includes all changes in equity during a period except those resulting from investments by owners and distributions to owners, but excludes any and all transactions which are directly or indirectly attributable to that ownership interest in subsidiary equity which is not attributable to the parent.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Accounting Research Bulletin (ARB)

-Number 51

-Paragraph A5

-Appendix A

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Accounting Research Bulletin (ARB)

-Number 51

-Paragraph 30

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Accounting Research Bulletin (ARB)

-Number 51

-Paragraph 38

-Subparagraph c(3)

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Accounting Research Bulletin (ARB)

-Number 51

-Paragraph 8, 9, 10, 11, 12, 13, 14

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- Definition

The portion of consolidated profit or loss for the period, net of income taxes, which is attributable to the parent. If the entity does not present consolidated financial statements, the amount of profit or loss for the period, net of income taxes.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 19

-Article 5

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Accounting Research Bulletin (ARB)

-Number 51

-Paragraph 38

-Subparagraph d

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Accounting Research Bulletin (ARB)

-Number 51

-Paragraph A7

-Appendix A

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Accounting Research Bulletin (ARB)

-Number 51

-Paragraph 38

-Subparagraph a

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Paragraph 20

-Article 9

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 130

-Paragraph 10, 15

Reference 7: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Emerging Issues Task Force (EITF)

-Number 87-21

Reference 8: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 28, 29, 30

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