Employee Benefit Plans - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Defined Benefit Plan Disclosure [Line Items]
Document Period End Date			Jun. 30, 2015
Expected pension and postretirement benefit costs			$ 1,200
Expected amortization of pre merger regulatory asset			769
Florida Public Utilities Company Medical Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost	$ 17	$ 16	33	$ 33
Contribution to pension plan	24		116
Defined Benefit Plans, Estimated Future Employer Contributions in Current Fiscal Year			207
Chesapeake Postretirement Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost	9	10	18	20
Contribution to pension plan	13		28
Defined Benefit Plans, Estimated Future Employer Contributions in Current Fiscal Year			79
Chesapeake Pension SERP [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost	50	40	101	79
Contribution to pension plan	38		71
Defined Benefit Plans, Estimated Future Employer Contributions in Current Fiscal Year			151
Consolidated [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost			(381)
Chesapeake Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost	58	12	115	23
Contribution to pension plan	115		219
Defined Benefit Plans, Estimated Future Employer Contributions in Current Fiscal Year			475
Florida Public Utilities Company Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Unamortized balance of regulatory asset	3,200		3,200		$ 3,600
Defined Benefit Plan, Net Periodic Benefit Cost	(37)	$ (125)	(76)	$ (251)
Contribution to pension plan	$ 381		723
Defined Benefit Plans, Estimated Future Employer Contributions in Current Fiscal Year			$ 1,600