Retirement plans

Our principal defined benefit pension plan is the TEGNA Retirement Plan (TRP). The disclosure table below includes the pension expenses of the TRP and the Supplemental Retirement Plan (SERP). In connection with our acquisition of KFMB, we assumed its preexisting pension plan which, as of the acquisition date, had a total net pension obligation of $7.3 million. All plan participants’ benefits were frozen prior to the acquisition date. During the second quarter of 2018, the KFMB pension plan was merged into the TRP. The total net pension obligations, including both current and non-current liabilities, as of September 30, 2018, were $130.9 million ($8.4 million is recorded as a current obligation within accrued liabilities on the Condensed Consolidated Balance Sheet).

Our pension costs, which primarily include costs for the qualified TRP and the non-qualified SERP, are presented in the following table (in thousands):



	Quarter ended Sept. 30,						Nine months ended Sept. 30,
	2018			2017			2018			2017

Service cost-benefits earned during the period	$	3		$	218		$	9		$	654
Interest cost on benefit obligation	5,721			5,990			15,945			17,971
Expected return on plan assets	(8,218		)	(6,580		)	(23,148		)	(19,741		)
Amortization of prior service cost	42			159			126			476
Amortization of actuarial loss	1,271			2,081			3,814			6,242
Pension payment timing related charges	1,198			—			7,498			—
Expense for company-sponsored retirement plans	$	17		$	1,868		$	4,244		$	5,602

The service cost component of our pension expense is recorded within the operating expense line items Cost of revenue, Business units - Selling, general and administrative, and Corporate - General and administrative within the Consolidated Statements of Income. All other components of our pension expense are included within the Other non-operating items line item of the Consolidated Statements of Income.

During the nine months ended September 30, 2018 we made $11.1 million in cash contributions to the TRP. No additional contributions are expected for the remainder of 2018. We made $10.9 million in cash contributions to the TRP during the nine months ended September 30, 2017. During the nine months ended September 30, 2018 and 2017, we made benefit payments to participants of the SERP of $32.9 million and $7.2 million, respectively.

In the first and third quarters of 2018, we accelerated the recognition of previously deferred pension costs as a result of lump sum SERP payments made to certain former executives. The first and third quarter charges were $6.3 million and $1.2 million, respectively, and were reclassified from accumulated other comprehensive income (loss) into net periodic benefit cost.