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Retirement Plans (Plan's Allocated Target and Ranges and Actual Weighted Average Asset Allocation by Investment Categories) (Details) | 12 Months Ended |
--- | --- | ---
Dec. 31, 2011 | Dec. 31, 2010
Target Percentage [Abstract] |  |
Alternative Investments | 15.00% |
Cash and short-term investments | 0.00% |
Range Percentage, Minimum [Abstract] |  |
Alternative investments | 20.00% |
Cash and short-term investments | 0.00% |
Range Percentage, Maximum [Abstract] |  |
Alternative investments | 34.00% |
Cash and short-term investments | 5.00% |
Actual Percentage [Abstract] |  |
Alternative investments | 9.00% | 11.00%
Cash and short-term investments | 7.00% | 10.00%
Total | 100.00% | 100.00%
Maximum percentage of any security value of total plan's portfolio value that is allowed | 8.00% |
Maximum percentage of outstanding shares of any one corporation | 5.00% |
Large Capitalization Securities [Member] |  |
Target Percentage [Abstract] |  |
Equity | 24.00% |
Range Percentage, Minimum [Abstract] |  |
Equity | 17.00% |
Range Percentage, Maximum [Abstract] |  |
Equity | 31.00% |
Actual Percentage [Abstract] |  |
Equity | 18.00% | 19.00%
Small And Mid Capitalization Securities [Member] |  |
Target Percentage [Abstract] |  |
Equity | 10.00% |
Range Percentage, Minimum [Abstract] |  |
Equity | 6.00% |
Range Percentage, Maximum [Abstract] |  |
Equity | 14.00% |
Actual Percentage [Abstract] |  |
Equity | 8.00% | 9.00%
International Securities [Member] |  |
Target Percentage [Abstract] |  |
Equity | 10.00% |
Range Percentage, Minimum [Abstract] |  |
Equity | 6.00% |
Range Percentage, Maximum [Abstract] |  |
Equity | 14.00% |
Actual Percentage [Abstract] |  |
Equity | 7.00% | 8.00%
Domestic Core Debt Securities [Member] |  |
Target Percentage [Abstract] |  |
Fixed income | 16.00% |
Range Percentage, Minimum [Abstract] |  |
Fixed Income | 0.00% |
Range Percentage, Maximum [Abstract] |  |
Fixed Income | 21.00% |
Actual Percentage [Abstract] |  |
Fixed income | 17.00% | 15.00%
Global Emerging Market Debt Securities [Member] |  |
Target Percentage [Abstract] |  |
Fixed income | 13.00% |
Range Percentage, Minimum [Abstract] |  |
Fixed Income | 0.00% |
Range Percentage, Maximum [Abstract] |  |
Fixed Income | 18.00% |
Actual Percentage [Abstract] |  |
Fixed income | 14.00% | 12.00%
Liability Driven Debt Investments [Member] |  |
Target Percentage [Abstract] |  |
Fixed income | 12.00% |
Range Percentage, Minimum [Abstract] |  |
Fixed Income | 0.00% |
Range Percentage, Maximum [Abstract] |  |
Fixed Income | 45.00% |
Actual Percentage [Abstract] |  |
Fixed income | 20.00% | 16.00%

X
- Definition The percentage of the fair value of alternative investment securities to the fair value of total plan assets held as of the measurement date. + References No definition available. + Details
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- Definition The percentage of cash and the fair value of short-term investment securities to the fair value of total plan assets held as of the measurement date. + References No definition available. + Details
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- Definition Target allocation percentage of investments in alternative investments 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 alternative investmenets 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 alternative investments 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 cash and short-term investments 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 cash and investments in short-term investments 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 maximum percentage of outstanding shares of any one corporation that is allowed for the Retirement Income Plan. + References No definition available. + Details
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- Definition The maximum percentage of any individual security value of the total Retirement Income Plan's portfolio value that is allowed. + References No definition available. + Details
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- Definition 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 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 Target allocation 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 + 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 + Details
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- Definition Target allocation 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 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 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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