Retirement Plans (Tables)

9 Months Ended

Sep. 30, 2021

Compensation And Retirement Disclosure [Abstract]

Components of Net Periodic Benefits Cost

The following tables show the components of net periodic benefit cost included in expense for the periods indicated.

							Other Post-
(in thousands)	Pension Benefits						Retirement Benefits
For The Three Months Ended September 30,	2021			2020			2021			2020
Service cost	$	2,620		$	3,207		$	23		$	28
Interest cost		3,552			3,892			91			106
Expected return on plan assets		(11,463	)		(12,047	)		—			—
Amortization of net (gain) or loss and prior service costs		717			1,854			(192	)		(142	)
Net periodic benefit cost	$	(4,574	)	$	(3,094	)	$	(78	)	$	(8	)

							Other Post-
(in thousands)	Pension Benefits						Retirement Benefits
For the Nine Months Ended September 30,	2021			2020			2021			2020
Service cost	$	8,996		$	9,690		$	71		$	78
Interest cost		9,982			12,315			257			377
Expected return on plan assets		(34,854	)		(36,144	)		—			—
Amortization of net (gain) or loss and prior service costs		4,471			5,168			(501	)		(512	)
Special termination benefits		16,052			—			4,137			—
Net periodic benefit cost	$	4,647		$	(8,971	)	$	3,964		$	(57	)