Employee Benefit Plans (Detail) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2022	Mar. 31, 2021
Defined Benefit Plan Disclosure [Line Items]
Amortization of prior service cost		$ (19)	$ (19)
Defined Benefit Plan Actuarial Gain Loss, Net Settlement			209
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)		143	228
Defined Benefit Plan Amounts Recognized Gain (Loss)		124	209
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, before Tax	[1]	24	85
Defined Benefit Plan Amounts Recognized From Regulatory Asset		100	124
Deferred Pension Settlement Expense		600
Chesapeake Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Interest cost		0	34
Expected return on plan assets		0	(40)
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)		0	60
Total periodic cost		0	54
Defined Benefit Plan Amounts Recognized Gain (Loss)		0	60
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, before Tax	[1]	0	60
Florida Public Utilities Company Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Interest cost		449	429
Expected return on plan assets		(857)	(830)
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)		124	155
Total periodic cost		(284)	(246)
Defined Benefit Plan Amounts Recognized Gain (Loss)		124	155
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, before Tax	[1]	24	29
Defined Benefit Plan Amounts Recognized From Regulatory Asset		100	126
Defined Benefit Plan, Expected Future Employer Contributions, Remainder of Fiscal Year		300
Chesapeake Pension SERP [Member]
Defined Benefit Plan Disclosure [Line Items]
Interest cost		13	12
Defined Benefit Plan Actuarial Gain Loss, Net Settlement			7
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)		7	7
Total periodic cost		20	19
Defined Benefit Plan Amounts Recognized Gain (Loss)		7	7
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, before Tax	[1]	7	7
Defined Benefit Plan, Expected Future Employer Contributions, Remainder of Fiscal Year		200
Chesapeake Postretirement Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Contributions by Employer		100
Interest cost		6	6
Amortization of prior service cost		(19)	(19)
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)		12	8
Total periodic cost		(1)	(5)
Defined Benefit Plan Amounts Recognized Gain (Loss)		(7)	(11)
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, before Tax	[1]	(7)	(11)
Defined Benefit Plan, Expected Future Employer Contributions, Remainder of Fiscal Year		100
Florida Public Utilities Company Medical Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Interest cost		6	6
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)			(2)
Total periodic cost		6	4
Defined Benefit Plan Amounts Recognized Gain (Loss)			(2)
Defined Benefit Plan Amounts Recognized From Regulatory Asset			$ (2)
Defined Benefit Plan, Expected Future Employer Contributions, Remainder of Fiscal Year		$ 100

[1] See Note 9, Stockholders' Equity.