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RETIREMENT PLANS: (Details 4) | 12 Months Ended
--- | ---
Dec. 31, 2015 | Dec. 31, 2014
Defined Benefit Plan Disclosure [Line Items] |  |
Percentage of plan assets (percent) | 100.00% | 100.00%
Employee Stock Ownership Plan |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Percentage of plan assets (percent) | 100.00% | 100.00%
Other Securities [Member] |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Percentage of plan assets (percent) | 2.00% | 3.00%
Other Securities [Member] | Employee Stock Ownership Plan |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Percentage of plan assets (percent) | 0.00% | 1.00%
Equity Securities |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Target plan asset allocations range minimum (percent) | 40.00% |
Target plan asset allocations range maximum (percent) | 65.00% |
Percentage of plan assets (percent) | 63.00% | 59.00%
Equity Securities | Employee Stock Ownership Plan |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Target plan asset allocations range minimum (percent) | 95.00% |
Target plan asset allocations range maximum (percent) | 99.00% |
Percentage of plan assets (percent) | 100.00% | 99.00%
Debt securities |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Target plan asset allocations range minimum (percent) | 35.00% |
Target plan asset allocations range maximum (percent) | 60.00% |
Percentage of plan assets (percent) | 35.00% | 38.00%
Debt securities | Employee Stock Ownership Plan |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Target plan asset allocations range minimum (percent) | 0.00% |
Target plan asset allocations range maximum (percent) | 0.00% |
Percentage of plan assets (percent) | 0.00% | 0.00%
Other Security Investments [Member] |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Target plan asset allocations range minimum (percent) | 0.00% |
Target plan asset allocations range maximum (percent) | 10.00% |
Other Security Investments [Member] | Employee Stock Ownership Plan |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Target plan asset allocations range minimum (percent) | 0.00% |
Target plan asset allocations range maximum (percent) | 5.00% |

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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 5 -Subparagraph (c)(i) -URI http://asc.fasb.org/extlink&oid=58740216&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)(i) -URI http://asc.fasb.org/extlink&oid=58740216&loc=d3e1928-114920 + Details
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