Note E - Benefit Plans (Details Textual) - DC Plan [Member] - USD ($)	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay	4.00%	4.00%
Defined Contribution, Discretionary Contribution Plan, Vesting Period	1 year
Defined Contribution Plan, Employer Discretionary Contribution Amount	$ 94,000	$ 87,000
Defined Contribution Plan, Employer Discretionary Contribution Amount Per Year Authorized	$ 175,000	$ 175,000
Discretionary Contributions Vesting at Two Years [Member]
Defined Contribution, Discretionary Contribution Plan, Vesting Period	2 years
Defined Contribution Plan, Employers Matching Contribution, Annual Vesting Percentage	20.00%
Discretionary Contributions Vesting Each Additional Year [Member]
Defined Contribution, Discretionary Contribution Plan, Vesting Period	6 years
Defined Contribution Plan, Employers Matching Contribution, Annual Vesting Percentage	20.00%

Represents the vesting period of discretionary contributions made under the defined contribution plan.

No definition available.

Name:	ug_DefinedContributionDiscretionaryContributionPlanVestingPeriod
Namespace Prefix:	ug_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Defined Contribution Plan, Employer Discretionary Contribution Amount Per Year, Authorized.

No definition available.

Name:	ug_DefinedContributionPlanEmployerDiscretionaryContributionAmountPerYearAuthorized
Namespace Prefix:	ug_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Amount of discretionary contributions made by an employer to a defined contribution plan.

No definition available.

Name:	us-gaap_DefinedContributionPlanEmployerDiscretionaryContributionAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Percentage of employees' gross pay for which the employer contributes a matching contribution to a defined contribution plan.

No definition available.

Name:	us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Percentage of employer's matching contributions to a defined contribution plan that vests in a given year.

No definition available.

Name:	us-gaap_DefinedContributionPlanEmployersMatchingContributionAnnualVestingPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Name:	us-gaap_RetirementPlanNameAxis=ug_DCPlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_StatementScenarioAxis=ug_DiscretionaryContributionsVestingAtTwoYearsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_StatementScenarioAxis=ug_DiscretionaryContributionsVestingEachAdditionalYearMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: