Employee Benefit Plans - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Defined Benefit Plan Disclosure [Line Items]
Expected pension and postretirement benefit costs			$ 1,600
Expected amortization of pre merger regulatory asset			769
Chesapeake Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost	$ 77	$ 58	155	$ 115
Contribution to pension plan	170		274
Defined Benefit Plans, Estimated Future Employer Contributions in Current Fiscal Year			508
Florida Public Utilities Company Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Unamortized balance of regulatory asset	2,500		2,500		$ 2,900
Defined Benefit Plan, Net Periodic Benefit Cost	57	(37)	114	(76)
Contribution to pension plan	548		885
Defined Benefit Plans, Estimated Future Employer Contributions in Current Fiscal Year			1,600
Chesapeake Pension SERP [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost	45	50	90	101
Contribution to pension plan	38		76
Defined Benefit Plans, Estimated Future Employer Contributions in Current Fiscal Year			151
Chesapeake Postretirement Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost	8	9	15	18
Contribution to pension plan	15		36
Defined Benefit Plans, Estimated Future Employer Contributions in Current Fiscal Year			82
Florida Public Utilities Company Medical Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost	14	$ 17	28	$ 33
Contribution to pension plan	$ 27		67
Defined Benefit Plans, Estimated Future Employer Contributions in Current Fiscal Year			149
Consolidated [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost			$ (802)