Compensation And Retirement Disclosure [Abstract]

Components of Net Periodic (Benefits) Cost

The following table shows net periodic (benefit) cost included in expense and the changes in the amounts recognized in AOCI during 2022, 2021, and 2020.


	Years Ended December 31,
	2022			2021			2020			2022			2021			2020
($ in thousands)	Pension Benefits									Other Post-Retirement Benefits
Net periodic (benefit) cost
Service cost	$	11,438		$	11,616		$	12,898		$	59		$	93		$	105
Interest cost		14,639			13,476			16,207			375			348			484
Expected return on plan assets		(46,615	)		(46,654	)		(48,191	)		—			—			—
Special termination benefits		—			16,052			—			—			4,173			—
Amortization of net (gain) loss/prior service cost		2,830			5,284			7,021			(650	)		(729	)		(653	)
Net periodic (benefit) cost		(17,708	)		(226	)		(12,065	)		(216	)		3,885			(64	)
Other changes in plan assets and benefit obligations recognized in other comprehensive income, before taxes
Net (loss) gain recognized during the year		(2,830	)		(5,284	)		(7,021	)		650			729			653
Net actuarial loss (gain)		29,952			(51,365	)		35,539			(5,906	)		(1,506	)		1,912
Total recognized in other comprehensive income		27,122			(56,649	)		28,518			(5,256	)		(777	)		2,565
Total recognized in net periodic benefit cost and other comprehensive income	$	9,414		$	(56,875	)	$	16,453		$	(5,472	)	$	3,108		$	2,501
Discount rate for benefit obligations		5.00	%		2.77	%		2.40	%		4.98	%		2.32	%		2.31	%
Discount rate for net periodic benefit cost		2.77	%		2.40	%		3.14	%		2.32	%		2.31	%		3.11	%
Expected long-term return on plan assets		5.50	%		5.75	%		6.50	%	n/a			n/a			n/a
Rate of compensation increase	scaled **			scaled **			scaled *			n/a			n/a			n/a

*Graded scale, declining from 7.25% at age 20 to 2.25% at age 60

** Graded scale, declining from 7.25% at age 20 to 2.25% at age 65

Fair Values of Pension Plan Assets

For all investments, the plan attempts to use quoted market prices of identical assets on active exchanges, or Level 1 measurements. Where such quoted market prices are not available, the plan will use quoted prices for similar instruments or discounted cash flows to estimate the value, reported as Level 2.


	December 31, 2022
Fair Value Measurements by Asset Category / Fund	Level 1		Level 2		Level 3		Total
($ in thousands)
Cash and equivalents	$	9,050		—		—	$	9,050
Total cash and cash equivalents		9,050		—		—		9,050
Fixed income securities		29,577		31,268		—		60,845
Mutual fund-fixed income		344		—		—		344
Exchange Traded Fund (ETF)-Fixed income		5,087		—		—		5,087
Total fixed income		35,008		31,268		—		66,276
Domestic and foreign stock		50,956		—		—		50,956
Mutual funds-equity		105,486		—		—		105,486
Total equity		156,442				—		156,442
Total assets at fair value		200,500		31,268		—		231,768
Common trust funds (fixed income)		—		—		—		410,280
Common trust fund (real assets)		—		—		—		58,487
Total	$	200,500	$	31,268		—	$	700,535


	December 31, 2021
Fair Value Measurements by Asset Category / Fund	Level 1		Level 2		Level 3		Total
($ in thousands)
Cash and equivalents	$	21,280		—		—	$	21,280
Total cash and cash equivalents		21,280		—		—		21,280
Fixed income securities		29,687		40,254		—		69,941
Mutual fund-fixed income		20,428		—		—		20,428
Exchange Traded Fund (ETF)-Fixed income		4,049		—		—		4,049
Total fixed income		54,164		40,254		—		94,418
Domestic and foreign stock		109,610		—		—		109,610
Mutual funds-equity		270,863		—		—		270,863
Total equity		380,473				—		380,473
Total assets at fair value		455,917		40,254		—		496,171
Common trust funds (fixed income)		—		—		—		294,112
Common trust fund (real assets)		—		—		—		69,600
Total	$	455,917	$	40,254		—	$	859,883