Amount of contribution received by defined benefit plan from employer which increases plan assets.

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Amount of decrease in accumulated postretirement benefit obligation from one-percentage-point decrease in assumed health care cost trend rate.

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Amount of cash outflow for pension benefit. Includes, but is not limited to, employer contribution to fund plan asset and payment to retiree. Excludes other postretirement benefit.

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Pension Plans And Other Postretirement Benefit Plans (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Other Operating Activities, Cash Flow Statement	$ 1,114	$ 1,860	$ 5,557
Percentage point increases in accumulated postretirement benefit obligation	8,100
Percentage point increase in service and interest cost	600
Percentage point decrease in accumulated postretirement benefit obligation	6,400
Percentage point decrease in service and interest cost	500
Payment for Pension Benefits	22,000	22,000	$ 12,000
Pension Plan And SERP [Member]
Defined Benefit Plan Disclosure [Line Items]
Contributions to defined benefit pension plan	22,000	22,000
Expected contributions to pension plan	22,000
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Contributions to defined benefit pension plan	0	$ 0
Expected contributions to pension plan	$ 7,100
Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Target investment allocation	37.00%	37.00%
Equity Securities [Member] \| Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Target investment allocation	60.00%	60.00%
Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Target investment allocation	45.00%	45.00%
Debt Securities [Member] \| Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Target investment allocation	40.00%	40.00%