Pension Plans And Other Postretirement Benefits (Tables)

9 Months Ended

Sep. 30, 2020

Components Of Net Periodic Benefit Costs

	Pension Benefits
	Three Months Ended				Nine Months Ended
	September 30,				September 30,
	2020		2019		2020		2019
Service cost	$	763	$	680	$	2,289	$	2,040
Interest cost		2,540		2,954		7,620		8,862
Expected return on plan assets		(3,938)		(3,818)		(11,814)		(11,454)
Amortization of prior service cost		148		155		444		465
Amortization of actuarial loss		1,992		1,982		5,976		5,946
Net periodic benefit cost	$	1,505	$	1,953	$	4,515	$	5,859
	Other
	Postretirement Benefits
		Three Months Ended				Nine Months Ended
		September 30,				September 30,
	2020		2019		2020		2019
Service cost	$	217	$	205	$	651	$	615
Interest cost		677		750		2,031		2,250
Expected return on plan assets		(675)		(621)		(2,025)		(1,863)
Amortization of prior service credit		(116)		(116)		(348)		(348)
Amortization of actuarial loss		156		166		468		498
Net periodic benefit cost	$	259	$	384	$	777	$	1,152

Peoples Gas Acquisition [Member]

Components Of Net Periodic Benefit Costs

	Three Months Ended				Nine Months Ended
	September 30, 2020				September 30, 2020
	Pension Benefits		Other Postretirement Benefits		Pension Benefits		Other Postretirement Benefits
Service cost	$	229	$	445	$	494	$	963
Interest cost		1,102		312		2,383		676
Expected return on plan assets		(1,738)		(436)		(3,759)		(944)
Net periodic benefit (income) cost	$	(407)	$	321	$	(882)	$	695