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General - Real Estate Investments (Details) $ in Thousands			3 Months Ended		9 Months Ended
	Jun. 29, 2021 USD ($)	Sep. 28, 2020 USD ($) property	Sep. 30, 2021 USD ($)	Sep. 30, 2020 USD ($)	Sep. 30, 2021 USD ($)	Sep. 30, 2020 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2017 USD ($)
Real Estate Properties [Line Items]
Land			$ 14,168		$ 14,168		$ 14,168
Buildings and improvements			44,597		44,597		43,961
Subtotal			58,765		58,765		58,129
Less accumulated depreciation and amortization			15,655		15,655		14,783
Real estate investments, net			43,110		43,110		$ 43,346
Sales agreement, holdback amount								$ 3,000
Gain on sale of real estate investments	$ 3,000		$ 0	$ 0	$ 3,000	$ 0
San Jose Water Company
Real Estate Properties [Line Items]
Gain on sale of real estate investments		$ 1,048
Number of properties sold | property		6
Proceeds from sale of real estate held-for-investment		$ 1,075
Real estate selling expenses		$ 22

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Number Of Properties Sold

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Real Estate Selling Expenses

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Sales Agreement, Holdback Amount

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The difference between the carrying value and the sale price of real estate or properties that were intended to be sold or held for capital appreciation or rental income. This element refers to the gain (loss) included in earnings and not to the cash proceeds of the sale. This element is a noncash adjustment to net income when calculating net cash generated by operating activities using the indirect method.

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Aggregate of the carrying amounts as of the balance sheet date of investments in building and building improvements.

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Amount before accumulated depletion of real estate held for productive use, excluding land held for sale.

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Cash received from the sale of real estate that is held for investment, that is, it is part of an investing activity during the period.

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The cumulative amount of depreciation for real estate property held for investment purposes.

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Amount of real estate investment property which may include the following: (1) land available-for-sale; (2) land available-for-development; (3) investments in building and building improvements; (4) tenant allowances; (5) developments in-process; (6) rental properties; and (7) other real estate investments.

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Amount of real estate investment property, net of accumulated depreciation, which may include the following: (1) land available-for-sale; (2) land available-for-development; (3) investments in building and building improvements; (4) tenant allowances; (5) developments in-process; (6) rental properties; and (7) other real estate investments.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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