Retirement Plans (Tables)

9 Months Ended

Sep. 30, 2019

Compensation And Retirement Disclosure [Abstract]

Components of Net Periodic Benefits Cost

							Other Post-
(in thousands)	Pension Benefits						Retirement Benefits
For the Three Months Ended September 30,	2019			2018			2019			2018
Service cost	$	2,735		$	3,163		$	22		$	28
Interest cost		4,659			4,279			165			161
Expected return on plan assets		(11,299	)		(10,375	)		—			—
Amortization of net loss and prior service costs		2,553			1,366			(229	)		(95	)
Net periodic benefit cost (reduction of cost)	$	(1,352	)	$	(1,567	)	$	(42	)	$	94

							Other Post-
(in thousands)	Pension Benefits						Retirement Benefits
For the Nine Months Ended September 30,	2019			2018			2019			2018
Service cost	$	8,245		$	9,251		$	73		$	91
Interest cost		14,183			12,481			457			459
Expected return on plan assets		(33,899	)		(30,244	)		—			—
Amortization of net loss and prior service costs		7,535			4,057			(684	)		(338	)
Net periodic benefit cost (reduction of cost)	$	(3,936	)	$	(4,455	)	$	(154	)	$	212