Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

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Period from grant date that an equity-based award expires, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Note 2 - Stock-based Compensation (Details Textual) - USD ($)	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Mar. 31, 2023	Dec. 31, 2022
CPHC Long Term Incentive Plan (LTI Plan) [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Number (in shares)	0
Non-Employee Board Member Stock Option and Restricted Stock [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period (in shares)	7,818
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value (in dollars per share)	$ 23.01
Non-Employee Board Member Stock Option and Restricted Stock [Member] \| Director [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period (Year)	10 years
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage	100.00%
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year)	1 year
Restricted Stock [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number (in shares)			0
Employee Deferred Stock Award [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year)	4 years	4 years
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period (in shares)	19,020	18,600
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value (in dollars per share)	$ 25.52	$ 21.62
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number (in shares)	38,220			41,200
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount	$ 862,000
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year)	3 years 9 months 18 days
Employee Deferred Stock Award [Member] \| CPHC Long Term Incentive Plan (LTI Plan) [Member]
Share-Based Payment Arrangement, Expense	$ 266,000	$ 215,000
Employee Deferred Stock Award [Member] \| Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year)	1 year
Employee Deferred Stock Award [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year)	4 years