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Share-Based Compensation Plans (Details Textual) (USD $) In Millions, except Share data, unless otherwise specified | 12 Months Ended
--- | ---
Dec. 31, 2012 OptionPlan | Dec. 31, 2011 | Dec. 31, 2010
Share-Based Compensation (Textual) [Abstract] |  |  |
Restricted Stock Units and Performance Awards at Target Level of Performance Included in Unvested Balance | 172,000 |  |
Restricted stock units and performance awards granted and remain outstanding at Dec. 31, 2012 |  |  | 24,000
Share-Based Compensation (Additional Textual) [Abstract] |  |  |
Number of active stock incentive plans | 1 |  |
Number of Inactive Stock Option plans | 1 |  |
Maximum duration over which stock options become exercisable under the plan | 60 months |  |
Termination date of the option from date of grant, in years | 10 years |  |
Maximum duration over which RSUs and PSAs become exercisable under the plan | 3 years |  |
Unrecognized compensation expense | $ 3.1 |  |
Expected period of compensation expense recognized | 1 year 7 months 6 days |  |
Number of common stock shares available for future issuance | 227,177 | 307,984 | 408,434
Intrinsic value, options exercised or exchanged | 0.1 | 0.8 | 0.8
Weighted average grant date fair value of options granted during 2010 |  |  | $ 15.35
Minimum Performance Awards issued multiplier | 0.00% |  |
Maximum Performance Awards issued multiplier | 200.00% |  |
Fair market value of stock option awards used in calculation of compensation expense, grant date | $ 23.40 | $ 25.15 | $ 23.81
Number of options granted During the period | 0 | 0 |
Director [Member] |  |  |
Share-Based Compensation (Textual) [Abstract] |  |  |
Stock awards granted to Non Employee Directors | 4,807 | 6,261 | 6,615
Maximum [Member] |  |  |
Share-Based Compensation (Textual) [Abstract] |  |  |
Vesting period of PSAs | 3 years |  |
Minimum [Member] |  |  |
Share-Based Compensation (Textual) [Abstract] |  |  |
Vesting period of PSAs | 2 years |  |
Performance Shares [Member] | Maximum [Member] |  |  |
Share-Based Compensation (Textual) [Abstract] |  |  |
Vesting period of PSAs | 3 years |  |
Performance Shares [Member] | Minimum [Member] |  |  |
Share-Based Compensation (Textual) [Abstract] |  |  |
Vesting period of PSAs | 3 months |  |
Restricted Stock Units and Performance Awards [Member] |  |  |
Share-Based Compensation (Textual) [Abstract] |  |  |
Restricted stock units and performance awards granted and remain outstanding at Dec. 31, 2012 | 47,000 |  |
Fair value of restricted stock units and performance awards vested | $ 0.6 | $ 0.4 | $ 0.8
Share-Based Compensation (Additional Textual) [Abstract] |  |  |
Number of restricted stock units and performance awards granted and remain outstanding | 115,306 | 174,891 |

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- Definition The number of non-vested equity-based payment instruments at a target level of performance, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date. + References No definition available. + Details
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- Definition Period over which an employee's right to exercise a PSA is no longer contingent on satisfaction of a service condition, market condition, or a performance condition, in years. + References No definition available. + Details
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- Definition Aggregate number of common shares reserved for future issuance. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 129 -Paragraph 4 -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 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.29) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
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- Definition The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(2)(iii)(1) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 123R -Paragraph A240 -Subparagraph b(2)(c) -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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- Definition The total fair value of equity-based awards for which the grantee gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash in accordance with the terms of the arrangement. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (d)(2) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 123R -Paragraph A240 -Subparagraph c(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. + Details
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- Definition The total accumulated difference between fair values of underlying shares on dates of exercise and exercise price on options which were exercised (or share units converted) into shares during the reporting period under the plan. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (d)(2) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 123R -Paragraph A240 -Subparagraph c(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. + Details
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- Definition Net number of share options (or share units) granted during the period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1)(iv)(1) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 123R -Paragraph A240 -Subparagraph b(1)(d) -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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