Retirement Benefit Plans (Tables)

6 Months Ended

Jun. 30, 2021

Retirement Benefits [Abstract]

Schedule of Defined Benefit Plans Disclosures

The following tables provide the components of net periodic benefit costs for the six month periods ended June 30, 2021 and 2020.

	Employees'		Select Executive		Postretirement
	Pension		Retirement		Benefit
	Plan		Plan		Plans
Net Periodic Cost (Benefit)
For the Three Months Ended June 30, 2021:
Service Cost 1	$	507	$	173	$	24
Interest Cost 2	343		50		57
Expected Return on Plan Assets 2	(940)		—		—
Amortization of Prior Service Cost 2	19		12		26
Amortization of Net Loss (Gain) 2	—		52		(52)
Net Periodic (Benefit) Cost	$	(71)	$	287	$	55
Plan Contributions During the Period	$	—	$	118	$	27

For the Three Months Ended June 30, 2020:
Service Cost 1	$	401	$	101	$	29
Interest Cost 2	355		42		77
Expected Return on Plan Assets 2	(900)		—		—
Amortization of Prior Service Cost 2	16		10		26
Amortization of Net Loss (Gain) 2	40		40		(2)
Net Periodic (Benefit) Cost	$	(88)	$	193	$	130
Plan Contributions During the Period	$	—	$	116	$	59
Net Periodic Benefit Cost
For the Six Months Ended June 30, 2021:
Service Cost 1	$	967	$	291	$	55
Interest Cost 2	683		95		124
Expected Return on Plan Assets 2	(1,890)		—		—
Amortization of Prior Service Cost 2	39		24		53
Amortization of Net Loss (Gain) 2	—		90		(44)
Net Periodic (Benefit) Cost	$	(201)	$	500	$	188
Plan Contributions During the Period	$	—	$	236	$	55
Estimated Future Contributions in the Current Fiscal Year	$	—	$	236	$	54
For the Six Months Ended June 30, 2020:
Service Cost 1	$	831	$	204	$	62
Interest Cost 2	772		96		155
Expected Return on Plan Assets 2	(1,804)		—		—
Amortization of Prior Service Cost 2	32		21		53
Amortization of Net Loss 2	41		73		—
Net Periodic (Benefit) Cost	$	(128)	$	394	$	270
Plan Contributions During the Period	$	—	$	233	$	137

Footnotes:

1. Included in Salaries and Employee Benefits on the Consolidated Statements of Income

2. Included in Other Operating Expense on the Consolidated Statements of Income