Benefits 10 (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011
Pension member
Defined Benefit Plan Disclosure [Line Items]
2012	$ 11,703
2013	11,860
2014	12,328
2015	12,031
2016	12,075
2017 - 2021	64,869
OPEB member
Defined Benefit Plan Disclosure [Line Items]
2012	4,798
2013	5,553
2014	6,422
2015	7,219
2016	7,960
2017 - 2021	48,348
Subsidy 2012	584
Subsidy 2013	606
Subsidy year 2014	712
Subsidy year 2015	819
Subsidy year 2016	958
Subsidy 2017 - 2021	$ 6,532

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The amount of the aggregate benefits expected to be paid in the five fiscal years thereafter (the aggregate amount of benefits expected to be paid in years 6 through 10 after the date of the latest statement of financial position).

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 132R

-Paragraph 5

-Subparagraph f

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (f)

-URI http://asc.fasb.org/extlink&oid=6962843&loc=d3e1928-114920

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- Definition

The amount of the benefits expected to be paid in Year 5.

+ References

+ Details

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- Definition

The amount of the benefits expected to be paid in Year 4.

+ References

+ Details

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- Definition

The amount of the benefits expected to be paid in Year 1.

+ References

+ Details

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- Definition

The amount of the benefits expected to be paid in Year 3.

+ References

+ Details

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- Definition

The amount of the benefits expected to be paid in Year 2.

+ References

+ Details

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- Definition

Aggregate amount for the next five fiscal years following the first five fiscal years (that is the aggregate of fiscal years six through ten) following the balance sheet date of the prescription drug subsidy receipts expected to be received.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 60

-Section 50

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=6414203&loc=d3e39716-114964

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 132R

-Paragraph 5

-Subparagraph f

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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

-Publisher FASB

-Name FASB Staff Position (FSP)

-Number FAS106-2

-Paragraph 22

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (f)

-URI http://asc.fasb.org/extlink&oid=6962843&loc=d3e1928-114920

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- Definition

Amount of the prescription drug subsidy receipts expected to be received in Year 5 after the balance sheet date.

+ References

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- Definition

Amount of the prescription drug subsidy receipts expected to be received in Year 4 after the balance sheet date.

+ References

+ Details

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- Definition

Amount of the prescription drug subsidy receipts expected to be received in Year 1 after the balance sheet date.

+ References

+ Details

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- Definition

Amount of the prescription drug subsidy receipts expected to be received in Year 3 after the balance sheet date.

+ References

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- Definition

Amount of the prescription drug subsidy receipts expected to be received in Year 2 after the balance sheet date.

+ References

+ Details

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