Pension and Postretirement Benefits (Tables)

6 Months Ended

Jun. 30, 2019

General Discussion Of Pension And Other Postretirement Benefits [Abstract]

Schedule Of Net Benefit Costs Table [Table Text Block]

	Three Months Ended June 30,								Six Months Ended June 30,
					Other								Other
					Postretirement								Postretirement
	Pension Benefits				Benefits				Pension Benefits				Benefits
		2019		2018		2019		2018		2019		2018		2019		2018
Service cost	$	978	$	960	$	2	$	3	$	1,963	$	1,948	$	4	$	5
Interest cost		1,105		1,032		36		33		2,216		2,081		71		66
Expected return on plan assets		(978)		(1,274)		—		—		(1,962)		(2,564)		—		—
Actuarial loss amortization		773		793		—		14		1,549		1,593		—		29
Prior service cost amortization		(41)		(29)		—		—		(83)		(60)		—		—
Net periodic benefit cost	$	1,837	$	1,482	$	38	$	50	$	3,683	$	2,998	$	75	$	100