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Note G - Pension and Other Postretirement Benefits (Details Textual) - USD ($) | 12 Months Ended
--- | ---
Dec. 31, 2015 | Dec. 31, 2014 | Dec. 31, 2013
Pension Plan [Member] | Minimum [Member] |  |  |
Defined Benefit Plans, Estimated Future Employer Contributions in Next Fiscal Year | $ 2,000,000 |  |
Pension Plan [Member] | Maximum [Member] |  |  |
Defined Benefit Plans, Estimated Future Employer Contributions in Next Fiscal Year | 6,000,000 |  |
Pension Plan [Member] |  |  |
Defined Contribution Plan, Employer Discretionary Contribution Amount | $ 1,600,000 | $ 1,600,000 | $ 1,300,000
Postretirement Health Coverage [Member] | Retirees Age65 And Over [Member] |  |  |
Defined Benefit Plan, Ultimate Health Care Cost Trend Rate | 0.00% |  |
Postretirement Health Coverage [Member] | Retirees Under Age65 [Member] |  |  |
Defined Benefit Plan, Ultimate Health Care Cost Trend Rate | 5.00% |  |
One Percentage Point Change in Assumed Rate of Return [Member] |  |  |
Defined Benefit Plan Effect On Pension Expense | $ 677,000 |  |
One Percentage Point Increase in Discount Rate [Member] |  |  |
Defined Benefit Plan Effect On Pension Expense | 1,600,000 |  |
One Percentage Point Decrease in Discount Rate [Member] |  |  |
Defined Benefit Plan Effect On Pension Expense | $ 1,900,000 |  |
Equity Securities [Member] |  |  |
Defined Benefit Plan, Target Plan Asset Allocations Range Minimum | 14.00% |  |
Defined Benefit Plan, Target Plan Asset Allocations Range Maximum | 34.00% |  |
Fixed Income Securities [Member] |  |  |
Defined Benefit Plan, Target Plan Asset Allocations Range Minimum | 60.00% |  |
Defined Benefit Plan, Target Plan Asset Allocations Range Maximum | 80.00% |  |
Alternative Investments [Member] |  |  |
Defined Benefit Plan, Target Plan Asset Allocations Range Minimum | 0.00% |  |
Defined Benefit Plan, Target Plan Asset Allocations Range Maximum | 12.00% |  |
Cash and Cash Equivalents [Member] |  |  |
Defined Benefit Plan, Target Plan Asset Allocations Range Minimum | 0.00% |  |
Defined Benefit Plan, Target Plan Asset Allocations Range Maximum | 10.00% |  |
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Settlements | $ 3,800,000 |  | $ 4,200,000
Unrecognized Actuarial Gain (Loss) in Excess of Benefit Obligation, Percentage | 10.00% |  |
Defined Benefit Plan, Effect of One Percentage Point Increase on Service and Interest Cost Components | $ 274,000 |  |
Defined Benefit Plan, Effect of One Percentage Point Increase on Accumulated Postretirement Benefit Obligation | 2,100,000 |  |
Defined Benefit Plan, Effect of One Percentage Point Decrease on Service and Interest Cost Components | 232,000 |  |
Defined Benefit Plan, Effect of One Percentage Point Decrease on Accumulated Postretirement Benefit Obligation | $ 1,800,000 |  |

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- Definition Unrecognized Actuarial Gain (Loss) in Excess of Benefit Obligation, Percentage. + References No definition available. + Details
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- Definition Amount of effect of a one-percentage-point decrease in the assumed health care cost trend rates on the accumulated postretirement benefit obligation for health care benefits. + 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 (m) -URI http://asc.fasb.org/extlink&oid=58740216&loc=d3e1928-114920 + Details
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- Definition Amount of effect of a one-percentage-point decrease in the assumed health care cost trend rates on the aggregate of the service and interest cost components of net periodic postretirement health care benefit costs. + 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 (m) -URI http://asc.fasb.org/extlink&oid=58740216&loc=d3e1928-114920 + Details
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- Definition The effect of a one-percentage-point increase in the assumed health care cost trend rates on the accumulated postretirement benefit obligation for health care benefits. + 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 (m) -URI http://asc.fasb.org/extlink&oid=58740216&loc=d3e1928-114920 + Details
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- Definition Amount of net gain (loss) recognized in net periodic benefit cost as a result of an irrevocable action that relieves the employer (or the plan) of primary responsibility for a benefit obligation and eliminates significant risks related to the obligation and the assets used to effect the settlement. Examples of transactions that constitute a settlement include, but are not limited to, lump-sum cash payments to plan participants in exchange for their rights to receive specified benefits and purchasing nonparticipating annuity contracts to cover vested benefits. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 30 -Section 15 -Paragraph 6 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=7577095&loc=d3e8001-114927 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (h)(7) -URI http://asc.fasb.org/extlink&oid=58740216&loc=d3e1928-114920 + Details
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- Definition Amount of employer's best estimate of contributions expected to be paid to the plan during the next fiscal year beginning after the date of the latest statement of financial position. + 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 (g) -URI http://asc.fasb.org/extlink&oid=58740216&loc=d3e1928-114920 + Details
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