Note 1 - Restatement of Previously Issued Financial Statements (Details Textual) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Liability for Claims and Claims Adjustment Expense, Current and Noncurrent	$ 33.6	$ 45.1

The current and noncurrent amount needed to reflect the estimated ultimate cost of settling claims relating to insured events that have occurred on or before the balance sheet date, whether or not reported to the insurer at that date.

No definition available.

Name:	gne_LiabilityForClaimsAndClaimsAdjustmentExpenseCurrentAndNoncurrent
Namespace Prefix:	gne_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant