XML 120 R74.htm IDEA: XBRL DOCUMENT v2.4.1.9
Stock-Based Compensation (Shares Authorized Under Stock Option Plans By Exercise Price Range) (Details) (USD $)
 12 Months Ended
Dec. 31, 2014
Stock Options | $37.69  
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]  
Outstanding and exercisable options, number of shares 9,500unt_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfOutstandingAndExercisableOptions
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
/ us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis
= unt_ThirtySevenPointSixNineMember
Outstanding and exercisable options weighted average remaining contractual life, years 4 months 24 days
Outstanding and exercisable options, weighted average exercise price $ 37.69unt_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeOutstandingAndExercisableOptionsWeightedAverageExercisePrice
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
/ us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis
= unt_ThirtySevenPointSixNineMember
Directors Plan | $31.30 - $41.21  
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]  
Minimum Limit $ 31.30us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLowerRangeLimit
/ us-gaap_AwardTypeAxis
= unt_DirectorsPlanMember
/ us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis
= unt_ThirtyOnePointThreeZeroToFortyOnePointTwoOneMember
Maximum limit $ 41.21us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit
/ us-gaap_AwardTypeAxis
= unt_DirectorsPlanMember
/ us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis
= unt_ThirtyOnePointThreeZeroToFortyOnePointTwoOneMember
Outstanding and exercisable options, number of shares 45,500unt_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfOutstandingAndExercisableOptions
/ us-gaap_AwardTypeAxis
= unt_DirectorsPlanMember
/ us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis
= unt_ThirtyOnePointThreeZeroToFortyOnePointTwoOneMember
Outstanding and exercisable options weighted average remaining contractual life, years 4 years 2 months 12 days
Outstanding and exercisable options, weighted average exercise price $ 37.88unt_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeOutstandingAndExercisableOptionsWeightedAverageExercisePrice
/ us-gaap_AwardTypeAxis
= unt_DirectorsPlanMember
/ us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis
= unt_ThirtyOnePointThreeZeroToFortyOnePointTwoOneMember
Directors Plan | $53.81 - $73.26  
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]  
Minimum Limit $ 53.81us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLowerRangeLimit
/ us-gaap_AwardTypeAxis
= unt_DirectorsPlanMember
/ us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis
= unt_FiftyThreePointEightOneToSeventyThreePointTwoSixMember
Maximum limit $ 73.26us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit
/ us-gaap_AwardTypeAxis
= unt_DirectorsPlanMember
/ us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis
= unt_FiftyThreePointEightOneToSeventyThreePointTwoSixMember
Outstanding and exercisable options, number of shares 105,000unt_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfOutstandingAndExercisableOptions
/ us-gaap_AwardTypeAxis
= unt_DirectorsPlanMember
/ us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis
= unt_FiftyThreePointEightOneToSeventyThreePointTwoSixMember
Outstanding and exercisable options weighted average remaining contractual life, years 3 years 6 months
Outstanding and exercisable options, weighted average exercise price $ 61.24unt_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeOutstandingAndExercisableOptionsWeightedAverageExercisePrice
/ us-gaap_AwardTypeAxis
= unt_DirectorsPlanMember
/ us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis
= unt_FiftyThreePointEightOneToSeventyThreePointTwoSixMember