The percent of face value of debt extinguished.

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- Definition

Marathon and United States Steel separated on January 1, 2002. Marathon continued to service long-term debt that is on U.S. Steel's books. In May 2010, U. S. Steel refinanced certain industrial development and environmental improvement bonds.

+ Details

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- Details

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- Definition

Carrying value as of the balance sheet date of short-term borrowings using unsecured obligations issued by banks, corporations and other borrowers to investors. The maturities of these money market securities generally do not exceed 270 days.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 16

-Article 7

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19

-Subparagraph a(3)

-Article 5

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 13

-Subparagraph 2

-Article 9

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- Definition

Interest rate stated in the contractual debt agreement.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

+ Details

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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- Definition

Date when the debt instrument is scheduled to be fully repaid, which may be presented in a variety of ways (year, month and year, day, month and year, quarter, etc.).

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 129

-Paragraph 2, 4

+ Details

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- Definition

Gross amount of debt extinguished.

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- Definition

Amount represents the difference between the fair value of the payments made and the carrying amount of the debt at the time of its extinguishment.

+ References

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

-Publisher AICPA

-Name Accounting Principles Board Opinion (APB)

-Number 26

-Paragraph 20, 21

+ Details

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- Definition

Amount borrowed under the credit facility as of the balance-sheet date.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 22

-Article 5

+ Details

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Debt (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended			9 Months Ended		12 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Jun. 30, 2010	Sep. 30, 2011	Sep. 30, 2010	Dec. 31, 2010
Debt Instrument [Line Items]
Extinguishment of debt amount			$ 500	$ 2,498
Loss on early extinguishment of debt	0	0		(279)	(92)
Debt Extinguished Percent Of Face Value						117.00%
Debt refinanced by United States Steel			89
Outstanding Short Term Debt [Abstract]
Commercial paper outstanding	0			0
Borrowings against revolving credit facility outstanding	0			0
Notes Due 2012 [A] [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	6.125%			6.125%
Extinguishment of debt amount				450
Debt Instrument, Maturity Date				Mar. 15, 2012
Notes Due 2012 [B] [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	6.00%			6.00%
Extinguishment of debt amount				400
Debt Instrument, Maturity Date				Jul. 01, 2012
Debentures Due 2014 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	6.50%			6.50%
Extinguishment of debt amount				700
Debt Instrument, Maturity Date				Feb. 15, 2014
Notes Due 2018 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	5.90%			5.90%
Extinguishment of debt amount				40
Debt Instrument, Maturity Date				Mar. 15, 2018
Debentures Due 2019 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	7.50%			7.50%
Extinguishment of debt amount				460
Debt Instrument, Maturity Date				Feb. 15, 2019
Consolidated Subsidiaries Secured Notes Due 2012 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	8.375%			8.375%
Extinguishment of debt amount				$ 448
Debt Instrument, Maturity Date				May 12, 2012