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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, 2012 | Dec. 31, 2011
Actual percentage | 100.00% | 100.00%
Maximum Percentage Of Any Security Value Of Total Plans Portfolio Vaue That Is Allowed | 8.00% |
Maximum Percentage Of Any Corporation Outstanding Shares That Is Allowed For Retirement Income Plan | 5.00% |
International Securities [Member] |  |
Target percentage | 10.00% |
Actual percentage | 7.00% | 7.00%
Range minimum | 4.00% |
Range maximum | 18.00% |
Large Capitalization Securities [Member] |  |
Target percentage | 15.00% |
Actual percentage | 15.00% | 18.00%
Range minimum | 8.00% |
Range maximum | 32.00% |
Small And Mid Capitalization Securities [Member] |  |
Target percentage | 5.00% |
Actual percentage | 7.00% | 8.00%
Range minimum | 3.00% |
Range maximum | 15.00% |
Global Asset Allocation [Member] |  |
Target percentage | 10.00% |
Actual percentage | 10.00% | 0.00%
Range minimum | 0.00% |
Range maximum | 15.00% |
Partnership Interest [Member] |  |
Target percentage | 10.00% |
Actual percentage | 6.00% | 9.00%
Range minimum | 0.00% |
Range maximum | 15.00% |
Extended Duration Fixed Income [Member] |  |
Target percentage | 50.00% |
Actual percentage | 24.00% | 20.00%
Range minimum | 20.00% |
Range maximum | 80.00% |
Domestic Core Debt Securities [Member] |  |
Actual percentage | 14.00% | 17.00%
Global bond high yield emerging markets [Member] |  |
Actual percentage | 13.00% | 14.00%
Cash and short term investments [Member] |  |
Target percentage | 0.00% |
Actual percentage | 4.00% | 7.00%
Range minimum | 0.00% |
Range maximum | 5.00% |

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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 Target allocation of investments of this type to total plan assets presented on a weighted average basis. + References Reference 1: 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=21915506&loc=d3e1928-114920 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=21915506&loc=d3e2446-114920 + Details
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- Definition Target allocation maximum percentage of investments of this type to total plan assets presented on a weighted average basis. + References Reference 1: 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=21915506&loc=d3e1928-114920 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=21915506&loc=d3e2446-114920 + Details
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- Definition Target allocation minimum percentage of investments of this type to total plan assets presented on a weighted average basis. + References Reference 1: 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=21915506&loc=d3e1928-114920 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=21915506&loc=d3e2446-114920 + Details
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- Definition Percentage of fair value of investments (categorized by debt securities, equity securities, real estate and other plan assets) to the fair value of plan assets held. + References Reference 1: 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=21915506&loc=d3e2446-114920 Reference 2: 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=21915506&loc=d3e1928-114920 Reference 3: 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. + Details
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