Name:	tris_DefinedBenefitPlanThresholdUnrecognizedAmountOfActuarialGainsAndLossesAsPercentageOfAccumulatedPostretirementBenefitObligation
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Amount of gain (loss) from change in actuarial assumptions which (increases) decreases benefit obligation of defined benefit plan. Assumptions include, but are not limited to, interest, mortality, employee turnover, salary, and temporary deviation from substantive plan.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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Amount of actuarial present value of benefits attributed to service rendered by employee for defined benefit plan.

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

No definition available.

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Amount of cost recognized for passage of time related to defined benefit plan.

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Amount of increase (decrease) in benefit obligation of defined benefit plan from change in terms of existing plan or initiation of new plan.

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Amount of cost for actuarial present value of benefits attributed to service rendered by employee for defined benefit plan.

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