EMPLOYEE BENEFIT PLANS (Tables)

12 Months Ended

Dec. 31, 2019

EMPLOYEE BENEFIT PLANS

Schedule of the postretirement medical benefit and postemployment medical benefit obligations

The postretirement medical benefit and postemployment medical benefit obligations are determined annually (during the fourth quarter) by an independent actuary and are included in accumulated postretirement benefit and postemployment obligations on our consolidated statements of financial position as follows (dollars in thousands):

	2019		2018
Postretirement medical benefit obligation at beginning of period	$	8,556	$	8,455
Service cost		563		677
Interest cost		352		288
Benefit payments (net of contributions by participants)		(617)		(408)
Actuarial loss (gain)		1,341		(456)
Postretirement medical benefit obligation at end of period	$	10,195	$	8,556
Postemployment medical benefit obligation at end of period		375		371
Total postretirement and postemployment medical obligations at end of period	$	10,570	$	8,927

Schedule of the net unrecognized actuarial gains and losses related to the postretirement medical benefit obligation that are included in accumulated other comprehensive income

The net unrecognized actuarial gains and losses related to the postretirement medical benefit obligation are included in accumulated other comprehensive income as follows (dollars in thousands):

	2019		2018
Amounts included in accumulated other comprehensive income at beginning of period	$	375	$	(369)
Amortization of actuarial (gain) loss into income		(342)		367
Amortization of prior service cost into other income		(79)		(79)
Actuarial (loss) gain		(1,341)		456
Amounts included in accumulated other comprehensive income at end of period	$	(1,387)	$	375

Schedule of assumptions used in actuarial study performed for postretirement medical benefit obligation

The assumptions used in the 2019 actuarial study performed for our postretirement medical benefit obligation were as follows:

Weighted-average discount rate	4.10	%
Initial health care cost trend (2018)	8.00	%
Ultimate health care cost trend	4.50	%
Year that the rate reached the ultimate health care cost trend rate	2027
Expected return on plan assets (unfunded)	N/A
Average remaining service lives of active plan participants (years)	12.35

Schedule of changes in the assumed health care cost trend rates and their impact on the accumulated postretirement medical benefit obligation and the net periodic postretirement medical benefit expense

Changes in the assumed health care cost trend rates would impact the accumulated postretirement medical benefit obligation and the net periodic postretirement medical benefit expense as follows (dollars in thousands):

	1% Increase		1% Decrease
Accumulated postretirement medical benefit obligation	$	1,159	$	(992)
Net periodic postretirement medical benefit expense		138		(116)

Schedule of the expected future benefits to be paid related to the postretirement medical benefit obligation

The following are the expected future benefits to be paid (net of contributions by participants) related to the postretirement medical benefit obligation during the next ten years (dollars in thousands):

2020	$	621
2021		719
2022		725
2023		685
2024		688
2025 through 2029		3,338
	$	6,776