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Retirement Plans And Postretirement Benefits (Narrative) (Details) $ in Millions |  | 12 Months Ended
--- | --- | ---
Mar. 27, 2015 USD ($) | Dec. 31, 2015 USD ($) years shares | Dec. 31, 2014 USD ($) shares | Dec. 31, 2013 USD ($) shares
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Percentage of increase in salaries based on the final average wages |  | 6.00% |  |
Percentage of equity in GTI |  | 50.00% |  |
Option to remain in defined benefit plan for an additional period, in years |  | 5 years |  |
Percentage of quarterly contributions to each employee's total eligible pay |  | 1.00% |  |
Pension and other postretirement benefit contributions |  | $ 0.6 | $ 0.8 | $ 0.9
Projected benefit obligations settled | $ 62.0 |  |  |
Defined benefit plan, accumulated benefit obligation |  | $ 158.9 | 237.0 |
Employee retirement age, years | years |  | 65 |  |
Assets of trust approximately |  | $ 0.8 | $ 5.2 |
Basic contribution to savings plan by employees in percentage |  | 5.00% |  |
Additional basic contribution to savings plan by employees in percentage |  | 45.00% |  |
Stock issued during period, shares, employee savings plan | shares |  | 321,107 | 581,006 | 553,298
Stock issued during period, value, employee benefit plan |  | $ 1.4 | $ 4.4 | $ 4.6
First Of Employee Contribution [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Units of fund that invest in our common stock |  | 3.00% | 3.00% | 3.00%
Employee contribution percent |  | 100.00% | 100.00% | 100.00%
Next of Employee Contribution [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Units of fund that invest in our common stock |  | 5.00% | 5.00% | 5.00%
Employee contribution percent |  | 20.00% | 20.00% | 20.00%
Equity Securities [Member] | U.S. [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Investment plan percentage |  | 20.00% |  |
Fixed Income Securities [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Investment plan percentage |  | 100.00% |  |
Fixed Income Securities [Member] | U.S. [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Investment plan percentage |  | 80.00% |  |

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- Definition The amount of decrease that relates to 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 (a) making lump-sum cash payments to plan participants in exchange for their rights to receive specified benefits and (b) purchasing nonparticipating annuity contracts. + 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 (a)(10) -URI http://asc.fasb.org/extlink&oid=58740216&loc=d3e1928-114920 + Details
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