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Note G - Pensions and Other Postretirement Benefits (Details Textual) - USD ($) | 12 Months Ended
--- | ---
Dec. 31, 2016 | Dec. 31, 2015 | Dec. 31, 2014
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Settlements | $ 0 | $ 3,800,000 | $ 0
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 | $ 270,000 |  |
Defined Benefit Plan, Effect of One Percentage Point Increase on Accumulated Postretirement Benefit Obligation | 2,000,000 |  |
Defined Benefit Plan, Effect of One Percentage Point Decrease on Service and Interest Cost Components | 231,000 |  |
Defined Benefit Plan, Effect of One Percentage Point Decrease on Accumulated Postretirement Benefit Obligation | $ 1,700,000 |  |
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% |  |
One Percentage Point Change in Assumed Rate of Return [Member] |  |  |
Defined Benefit Plan Effect On Pension Expense | $ 692,000 |  |
One Percentage Point Increase in Discount Rate [Member] |  |  |
Defined Benefit Plan Effect On Pension Expense | 1,400,000 |  |
One Percentage Point Decrease in Discount Rate [Member] |  |  |
Defined Benefit Plan Effect On Pension Expense | 1,700,000 |  |
Pension Plan [Member] |  |  |
Defined Contribution Plan, Employer Discretionary Contribution Amount | 1,600,000 | $ 1,600,000 | $ 1,600,000
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 |  |
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% |  |

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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=65897934&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=65897934&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=65897934&loc=d3e1928-114920 + Details
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