RETIREMENT PLANS: (Details 1) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Change in benefit obligation:
Benefit obligation at January 1	$ 84,908	$ 67,006
Service cost	4,872	3,542	3,093
Interest cost	3,667	3,688	3,313
Actuarial (gain) loss	(4,747)	12,689
Benefits paid	(1,893)	(2,017)
Benefit obligation at December 31	86,807	84,908	67,006
Reconciliation of fair value of plan assets:
Fair value of plan assets at January 1	53,935	48,464
Actual return on plan assets	371	(1,176)
Employer contributions	5,078	8,664
Benefits paid	(1,893)	(2,017)
Fair value of plan assets at December 31	57,491	53,935	48,464
Funded status at December 31 (plan assets less benefit obligation)	$ (29,316)	$ (30,973)

The difference between fair value of plan assets at the end of the period and the fair value at the beginning of the period, adjusted for contributions and payments of benefits during the period, and after adjusting for taxes and other expenses, as applicable.

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Amount of gain (loss) from a decision to temporarily deviate from the substantive plan, or from a change in benefit obligation or plan asset value from changes in actuarial assumptions, for example, but not limited to, interest, mortality, employee turnover or salary scale.

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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.

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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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