Retirement Plans and Other Postretirement Benefits

Substantially all employees who were hired before December 8, 2009 are covered by a noncontributory retirement plan. Employees hired on or after December 8, 2009 are not eligible to participate in the noncontributory retirement plan. The Corporation also provides supplemental executive retirement benefits to certain former executives, a portion of which is in excess of limits imposed on qualified plans by federal tax law; these plans are non-qualified benefit plans. These non-qualified benefit plans are not offered to new participants; all current participants are now retired. Information on these plans are aggregated and reported under “Retirement Plans” within this footnote.

The Corporation also provides certain postretirement healthcare and life insurance benefits for retired employees. Information on these benefits is reported under “Other Postretirement Benefits” within this footnote.

The Corporation sponsors a Supplemental Non-Qualified Pension Plan, which was established in 1981 prior to the existence of a 401(k) deferred salary savings plan, employee stock purchase plan and long-term incentive plans and therefore is not offered to new participants; all current participants are now retired.

Components of net periodic benefit cost (income) were as follows:



	Three Months Ended September 30,
	2018			2017			2018		2017
(Dollars in thousands)	Retirement Plans						Other Post Retirement Benefits
Service cost	$	140		$	124		$	22	$	12
Interest cost	440			487			23		29
Expected return on plan assets	(849		)	(797		)	—		—
Amortization of net actuarial loss	280			309			1		11
Accretion of prior service cost	(70		)	(71		)	—		—
Net periodic benefit (income) cost	$	(59	)	$	52		$	46	$	52



	Nine Months Ended September 30,
	2018			2017			2018		2017
(Dollars in thousands)	Retirement Plans						Other Post Retirement Benefits
Service cost	$	420		$	399		$	66	$	36
Interest cost	1,320			1,439			69		88
Expected return on plan assets	(2,440		)	(2,298		)	—		—
Amortization of net actuarial loss	841			886			3		32
Accretion of prior service cost	(212		)	(212		)	—		—
Net periodic benefit (income) cost	$	(71	)	$	214		$	138	$	156

The components of net periodic benefit cost other than the service cost component are included in other noninterest expense in the consolidated statements of income.

The Corporation made a contribution of $3.0 million to its qualified retirement plan on July 5, 2018. The Corporation previously disclosed in its financial statements for the year ended December 31, 2017 that it expected to make contributions of $158 thousand to its non-qualified retirement plans and $80 thousand to its other postretirement benefit plans in 2018. During the nine months ended September 30, 2018, the Corporation contributed $120 thousand to its non-qualified retirement plans and $79 thousand to its other postretirement plans. During the nine months ended September 30, 2018, $2.0 million was paid to participants from the retirement plans and $79 thousand was paid to participants from the other postretirement plans.