Retirement Plans

9 Months Ended

Sep. 30, 2021

Retirement Benefits [Abstract]

Retirement Plans

Retirement Plans

Net periodic pension expense for our DB plans includes the following components:

		3ME September 30,				9ME September 30,
(in thousands)	Location of Component	2021		2020		2021		2020
Service cost	Cost of revenue	$	4,293	$	4,442	$	13,084	$	12,843
Interest cost	Corp G&A	1,737		2,367		5,294		6,843
Expected return on assets	Corp G&A	(7,081)		(6,667)		(21,568)		(19,260)
Amortization of prior service credit	Corp G&A	(213)		(231)		(649)		(667)
Recognized net actuarial loss	Corp G&A	1,406		1,204		4,282		3,476
Net periodic pension expense		$	142	$	1,115	$	443	$	3,235

We currently expect to contribute up to $16 million into our DB plans during 2021, which we expect to be in excess of the minimum funding required. During the 2021 Period, we made contributions of approximately $13 million.

In addition to our DB plans, we participate in multiemployer pension plans for unionized construction and maintenance craft employees. Company contributions, based on the hours worked by employees covered under various collective bargaining agreements, are recognized as net periodic pension expense. Upon withdrawal from a multiemployer plan, we may have an obligation to make additional contributions for our share of any unfunded benefit obligation, but only if we do not meet the requirements of any applicable exemptions. For one of our discontinued operations, we participate in one multiemployer plan in which we are aware of a significant unfunded benefit obligation. However, we believe we qualify for an exemption and do not believe we have a probable payment to the plan. Therefore, we have not recognized a liability related to this unfunded benefit obligation.