Employee Benefit Plans (Detail) - USD ($) $ in Thousands		3 Months Ended				9 Months Ended
		Sep. 30, 2022		Sep. 30, 2021		Sep. 30, 2022		Sep. 30, 2021
Defined Benefit Plan Disclosure [Line Items]
Amortization of prior service cost		$ (19)		$ (19)		$ (57)		$ (57)
Defined Benefit Plan Actuarial Gain Loss, Net Settlement				211				633
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)		143		230		429		690
Defined Benefit Plan Amounts Recognized Gain (Loss)		124		211		372		633
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, before Tax		24	[1]	87	[1]	72	[2]	260	[2]
Defined Benefit Plan Amounts Recognized From Regulatory Asset		100		124		300		373
Deferred Pension Settlement Expense						600
Chesapeake Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Interest cost		0		34		0		102
Expected return on plan assets		0		(40)		0		(120)
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)		0		60		0		180
Total periodic cost		0		54		0		162
Defined Benefit Plan Amounts Recognized Gain (Loss)		0		60		0		180
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, before Tax		0	[1]	60	[1]	0	[2]	180	[2]
Florida Public Utilities Company Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Contributions by Employer						100
Interest cost		449		429		1,347		1,287
Expected return on plan assets		(857)		(830)		(2,571)		(2,490)
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)		124		155		372		465
Total periodic cost		(284)		(246)		(852)		(738)
Defined Benefit Plan Amounts Recognized Gain (Loss)		124		155		372		465
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, before Tax		24	[1]	29	[1]	72	[2]	87	[2]
Defined Benefit Plan Amounts Recognized From Regulatory Asset		100		126		300		378
Defined Benefit Plan, Expected Future Employer Contributions, Remainder of Fiscal Year		300				300
Chesapeake Pension SERP [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Contributions by Employer						100
Interest cost		13		12		39		36
Defined Benefit Plan Actuarial Gain Loss, Net Settlement				7				21
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)		7		7		21		21
Total periodic cost		20		19		60		57
Defined Benefit Plan Amounts Recognized Gain (Loss)		7		7		21		21
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, before Tax		7	[1]	7	[1]	21	[2]	21	[2]
Defined Benefit Plan, Expected Future Employer Contributions, Remainder of Fiscal Year		200				200
Chesapeake Postretirement Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Contributions by Employer		100				200
Interest cost		6		6		18		18
Amortization of prior service cost		(19)		(19)		(57)		(57)
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)		12		10		36		30
Total periodic cost		(1)		(3)		(3)		(9)
Defined Benefit Plan Amounts Recognized Gain (Loss)		(7)		(9)		(21)		(27)
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, before Tax		(7)	[1]	(9)	[1]	(21)	[2]	(27)	[2]
Defined Benefit Plan, Expected Future Employer Contributions, Remainder of Fiscal Year		200				200
Florida Public Utilities Company Medical Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Interest cost		6		6		18		18
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)				(2)				(6)
Total periodic cost		6		4		18		12
Defined Benefit Plan Amounts Recognized Gain (Loss)				(2)				(6)
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, before Tax	[2]							(1)
Defined Benefit Plan Amounts Recognized From Regulatory Asset				$ (2)				$ (5)
Defined Benefit Plan, Expected Future Employer Contributions, Remainder of Fiscal Year		$ 100				$ 100

[1] .

[2] 1) See Note 9, Stockholders' Equity.