Employee Benefit Plans (Detail) - USD ($) $ in Thousands		3 Months Ended				6 Months Ended
		Jun. 30, 2022		Jun. 30, 2021		Jun. 30, 2022		Jun. 30, 2021
Defined Benefit Plan Disclosure [Line Items]
Amortization of prior service cost		$ (19)		$ (19)		$ (38)		$ (38)
Defined Benefit Plan Actuarial Gain Loss, Net Settlement				211				420
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)		143		230		286		458
Defined Benefit Plan Amounts Recognized Gain (Loss)		124		211		248		420
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, before Tax		24	[1]	87	[1]	48	[2]	171	[2]
Defined Benefit Plan Amounts Recognized From Regulatory Asset		100		124		200		249
Deferred Pension Settlement Expense						600
Chesapeake Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Interest cost		0		34		0		68
Expected return on plan assets		0		(40)		0		(80)
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)		0		60		0		120
Total periodic cost		0		54		0		108
Defined Benefit Plan Amounts Recognized Gain (Loss)		0		60		0		120
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, before Tax		0	[1]	60	[1]	0	[2]	120	[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		898		858
Expected return on plan assets		(857)		(830)		(1,714)		(1,660)
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)		124		155		248		310
Total periodic cost		(284)		(246)		(568)		(492)
Defined Benefit Plan Amounts Recognized Gain (Loss)		124		155		248		310
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, before Tax		24	[1]	29	[1]	48	[2]	58	[2]
Defined Benefit Plan Amounts Recognized From Regulatory Asset		100		126		200		252
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		26		24
Defined Benefit Plan Actuarial Gain Loss, Net Settlement				7				14
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)		7		7		14		14
Total periodic cost		20		19		40		38
Defined Benefit Plan Amounts Recognized Gain (Loss)		7		7		14		14
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, before Tax		7	[1]	7	[1]	14	[2]	14	[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
Interest cost		6		6		12		12
Amortization of prior service cost		(19)		(19)		(38)		(38)
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)		12		10		24		18
Total periodic cost		(1)		(3)		(2)		(8)
Defined Benefit Plan Amounts Recognized Gain (Loss)		(7)		(9)		(14)		(20)
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, before Tax		(7)	[1]	(9)	[1]	(14)	[2]	(20)	[2]
Defined Benefit Plan, Expected Future Employer Contributions, Remainder of Fiscal Year		100				100
Florida Public Utilities Company Medical Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Interest cost		6		6		12		12
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)				(2)				(4)
Total periodic cost		6		4		12		8
Defined Benefit Plan Amounts Recognized Gain (Loss)				(2)				(4)
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, before Tax	[2]							(1)
Defined Benefit Plan Amounts Recognized From Regulatory Asset				$ (2)				$ (3)
Defined Benefit Plan, Expected Future Employer Contributions, Remainder of Fiscal Year		$ 100				$ 100

[1] .

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