Employee Benefit Plans Investment of Plan Assets (Details) (Pension Plans, Defined Benefit [Member])	12 Months Ended
Dec. 31, 2011	Dec. 31, 2010
Defined Benefit Plan, Actual Plan Asset Allocations [Abstract]
Real estate fund	3.00%	3.00%
Total	100.00%	100.00%
Defined Benefit Plan, Assets, Target Allocations [Abstract]
Real estate, range minimum	2.00%
Real estate, range maximum	4.00%
Domestic equity securities [Member]
Defined Benefit Plan, Actual Plan Asset Allocations [Abstract]
Equity securities	44.00%	44.00%
Defined Benefit Plan, Assets, Target Allocations [Abstract]
Equity securities, range minimum	40.00%
Equity securities, range maximum	45.00%
International equity securities [Member]
Defined Benefit Plan, Actual Plan Asset Allocations [Abstract]
Equity securities	20.00%	23.00%
Defined Benefit Plan, Assets, Target Allocations [Abstract]
Equity securities, range minimum	20.00%
Equity securities, range maximum	30.00%
Domestic fixed income securities [Member]
Defined Benefit Plan, Actual Plan Asset Allocations [Abstract]
Fixed income securities	28.00%	25.00%
Defined Benefit Plan, Assets, Target Allocations [Abstract]
Debt securities, range minimum	25.00%
Debt securities, range maximum	30.00%
International fixed income securities [Member]
Defined Benefit Plan, Actual Plan Asset Allocations [Abstract]
Fixed income securities	5.00%	5.00%
Defined Benefit Plan, Assets, Target Allocations [Abstract]
Debt securities, range minimum	4.00%
Debt securities, range maximum	6.00%

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The percentage of the fair value of debt securities to the fair value of total plan assets held as of the measurement date.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 132R

-Paragraph 5

-Subparagraph d(1)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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 5

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=6962843&loc=d3e2446-114920

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (d)(1)

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

+ Details

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- Definition

The percentage of the fair value of equity securities to the fair value of total plan assets held as of the measurement date.

+ References

+ Details

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- Definition

The percentage of the fair value of real estate to the fair value of total plan assets held as of the measurement date.

+ References

+ Details

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- Definition

Target allocation maximum percentage of investments in debt securities to total plan assets presented on a weighted-average basis as of the measurement date of the latest statement of financial position.

+ References

No definition available.

+ Details

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- Definition

Target allocation minimum percentage of investments in debt securities to total plan assets presented on a weighted-average basis as of the measurement 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 d(2)

-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 5

-Subparagraph (c)(i)

-URI http://asc.fasb.org/extlink&oid=6962843&loc=d3e2446-114920

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (d)(i)

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

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- Definition

Target allocation maximum percentage of investments in equity securities to total plan assets presented on a weighted-average basis as of the measurement date of the latest statement of financial position.

+ References

No definition available.

+ Details

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- Definition

Target allocation minimum percentage of investments in equity securities to total plan assets presented on a weighted-average basis as of the measurement date of the latest statement of financial position.

+ References

No definition available.

+ Details

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- Definition

Target allocation maximum percentage of investments in real estate to total plan assets presented on a weighted-average basis as of the measurement date of the latest statement of financial position.

+ References

No definition available.

+ Details

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- Definition

Target allocation minimum percentage of investments in real estate to total plan assets presented on a weighted-average basis as of the measurement date of the latest statement of financial position.

+ References

No definition available.

+ Details

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- Definition

The aggregate percentage of the fair value of investments (categorized by debt securities, equity securities, real estate and other plan assets) to the fair value of total plan assets held as of the measurement date.

+ References

+ Details

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