RETIREMENT PLANS: (Details 9) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Change in benefit obligation:
Benefit obligation at January 1	$ 81,469	$ 86,807
Service cost	2,040us-gaap_DefinedBenefitPlanServiceCost	2,238us-gaap_DefinedBenefitPlanServiceCost	4,872us-gaap_DefinedBenefitPlanServiceCost
Interest cost	3,756us-gaap_DefinedBenefitPlanInterestCost	3,383us-gaap_DefinedBenefitPlanInterestCost	3,667us-gaap_DefinedBenefitPlanInterestCost
Actuarial (gain) loss	22,274	(7,098)
Benefits paid	(4,256)us-gaap_DefinedBenefitPlanBenefitsPaid	(3,861)us-gaap_DefinedBenefitPlanBenefitsPaid
Benefit obligation at December 31	98,135	81,469	86,807
Funded status at December 31	(35,570)	(14,236)
Supplemental Employee Retirement Plans, Defined Benefit
Change in benefit obligation:
Benefit obligation at January 1	4,088	4,395
Service cost	53	68
Interest cost	175	173
Plan participants' contributions	39	37
Actuarial (gain) loss	456	(338)
Benefits paid	(252)	(247)
Benefit obligation at December 31	4,559	4,088
Funded status at December 31	$ 4,559	$ 4,088

Amount of gain (loss) related to change in benefit obligation resulting from changes in actuarial assumptions, for example, but not limited to, interest, mortality, employee turnover, salary, and temporary deviation from the substantive plan.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 30

-Glossary Gain or Loss

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- Definition

1) For defined benefit pension plans, the benefit obligation is the projected benefit obligation, which is the actuarial present value as of a date of all benefits attributed by the pension benefit formula to employee service rendered prior to that date. 2) For other postretirement defined benefit plans, the benefit obligation is the accumulated postretirement benefit obligation, which is the actuarial present value of benefits attributed to employee service rendered to a particular date.

+ References

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-Glossary Projected Benefit Obligation

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-Glossary Accumulated Postretirement Benefit Obligation

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The amount of payments made for which participants are entitled under a pension plan, including pension benefits, death benefits, and benefits due on termination of employment. Also includes payments made under a postretirement benefit plan, including prescription drug benefits, health care benefits, life insurance benefits, and legal, educational and advisory services. This item represents a periodic decrease to the plan obligations and a decrease to plan assets.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Postretirement Benefits

-URI http://asc.fasb.org/extlink&oid=6521376

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- Definition

The amount of contributions made by plan participants. This item represents a periodic increase to the plan obligation and an increase to plan assets.

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The funded status is measured as the difference between the fair value of plan assets and the benefit obligation. Will normally be the same as the net Defined Benefit Plan, Amounts Recognized in Balance Sheet, Total.

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The increase in a defined benefit pension plan's projected benefit obligation or a defined benefit postretirement plan's accumulated postretirement benefit obligation due to the passage of time.

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The actuarial present value of benefits attributed by the pension benefit formula to services rendered by employees during the period. The portion of the expected postretirement benefit obligation attributed to employee service during the period. The service cost component is a portion of the benefit obligation and is unaffected by the funded status of the plan.

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