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Long Term Debt - Additional Information (Detail) (USD $) | 12 Months Ended | 0 Months Ended | 12 Months Ended | 0 Months Ended |
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Dec. 31, 2014 | Dec. 31, 2013 | Dec. 31, 2012 | Sep. 27, 2012 LegalMatter | Aug. 19, 2010 | Oct. 05, 2010 LegalMatter | Dec. 31, 2010 | Jun. 14, 2012 LegalMatter | Apr. 01, 2015
Debt Disclosure [Line Items] |  |  |  |  |  |  |  |  |
Unfunded letters of credit, amount outstanding | $ 39,800,000 us-gaap_LettersOfCreditOutstandingAmount |  |  |  |  |  |  |  |
Line of credit, available borrowing capacity | 157,000,000 us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity |  |  |  |  |  |  |  |
Debt issuance costs |  |  | 7,581,000 us-gaap_PaymentsOfDebtIssuanceCosts |  |  |  |  |  |
Interest expense related to amortization of debt issuance costs | 2,200,000 us-gaap_AmortizationOfFinancingCosts | 2,200,000 us-gaap_AmortizationOfFinancingCosts | 3,400,000 us-gaap_AmortizationOfFinancingCosts |  |  |  |  |  |
London Interbank Offered Rate (LIBOR) |  |  |  |  |  |  |  |  |
Debt Disclosure [Line Items] |  |  |  |  |  |  |  |  |
Applicable margin | 2.25%pten_ApplicableMarginRate / us-gaap_VariableRateAxis = us-gaap_LondonInterbankOfferedRateLIBORMember |  |  |  |  |  |  |  |
London Interbank Offered Rate (LIBOR) | Scenario Forecast |  |  |  |  |  |  |  |  |
Debt Disclosure [Line Items] |  |  |  |  |  |  |  |  |
Applicable margin |  |  |  |  |  |  |  |  | 2.75%pten_ApplicableMarginRate / us-gaap_StatementScenarioAxis = us-gaap_ScenarioForecastMember / us-gaap_VariableRateAxis = us-gaap_LondonInterbankOfferedRateLIBORMember
Base Rate |  |  |  |  |  |  |  |  |
Debt Disclosure [Line Items] |  |  |  |  |  |  |  |  |
Applicable margin | 1.25%pten_ApplicableMarginRate / us-gaap_VariableRateAxis = us-gaap_BaseRateMember |  |  |  |  |  |  |  |
Base Rate | Scenario Forecast |  |  |  |  |  |  |  |  |
Debt Disclosure [Line Items] |  |  |  |  |  |  |  |  |
Applicable margin |  |  |  |  |  |  |  |  | 1.75%pten_ApplicableMarginRate / us-gaap_StatementScenarioAxis = us-gaap_ScenarioForecastMember / us-gaap_VariableRateAxis = us-gaap_BaseRateMember
Credit Agreement |  |  |  |  |  |  |  |  |
Debt Disclosure [Line Items] |  |  |  |  |  |  |  |  |
Credit facility, maximum borrowing capacity |  |  |  | 700,000,000 us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity / us-gaap_DebtInstrumentAxis = pten_CreditAgreementMember |  |  |  |  |
Debt maturity date |  |  |  | Sep. 27, 2017 |  |  |  |  |
Aggregate amount by which the revolving credit facility can be increased |  |  |  | 100,000,000 pten_LineOfCreditFacilityAdditionalBorrowingCapacity / us-gaap_DebtInstrumentAxis = pten_CreditAgreementMember |  |  |  |  |
Commitment fee payable to the lenders for the unused portion of the credit facility | 0.50%us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage / us-gaap_DebtInstrumentAxis = pten_CreditAgreementMember |  |  |  |  |  |  |  |
Credit agreement, financial covenant description | The Company must not permit its debt to capitalization ratio to exceed 45%. The Credit Agreement generally defines the debt to capitalization ratio as the ratio of (a) total borrowed money indebtedness to (b) the sum of such indebtedness plus consolidated net worth, with consolidated net worth determined as of the last day of the most recently ended fiscal quarter. The Company also must not permit the interest coverage ratio as of the last day of a fiscal quarter to be less than 3.00 to 1.00. The Credit Agreement generally defines the interest coverage ratio as the ratio of earnings before interest, taxes, depreciation and amortization (“EBITDA”) of the four prior fiscal quarters to interest charges for the same period. The Company was in compliance with these covenants at December 31, 2014. |  |  |  |  |  |  |  |
Number of compliance covenants |  |  |  | 2 pten_NumberOfCovenants / us-gaap_DebtInstrumentAxis = pten_CreditAgreementMember |  |  |  |  |
Credit Agreement | Minimum |  |  |  |  |  |  |  |  |
Debt Disclosure [Line Items] |  |  |  |  |  |  |  |  |
Interest coverage ratio that the Company must exceed on the last day of the fiscal quarter |  |  |  | 300.00%pten_InterestCoverageRatio / us-gaap_DebtInstrumentAxis = pten_CreditAgreementMember / us-gaap_RangeAxis = us-gaap_MinimumMember |  |  |  |  |
Credit Agreement | Maximum |  |  |  |  |  |  |  |  |
Debt Disclosure [Line Items] |  |  |  |  |  |  |  |  |
Debt to capitalization ratio, percentage the Company must not exceed at any time |  |  |  | 45.00%pten_ConsolidatedDebtAsPercentageOfCapitalization / us-gaap_DebtInstrumentAxis = pten_CreditAgreementMember / us-gaap_RangeAxis = us-gaap_MaximumMember |  |  |  |  |
Credit Agreement | London Interbank Offered Rate (LIBOR) | Minimum |  |  |  |  |  |  |  |  |
Debt Disclosure [Line Items] |  |  |  |  |  |  |  |  |
Applicable margin |  |  |  | 2.25%pten_ApplicableMarginRate / us-gaap_DebtInstrumentAxis = pten_CreditAgreementMember / us-gaap_RangeAxis = us-gaap_MinimumMember / us-gaap_VariableRateAxis = us-gaap_LondonInterbankOfferedRateLIBORMember |  |  |  |  |
Credit Agreement | London Interbank Offered Rate (LIBOR) | Maximum |  |  |  |  |  |  |  |  |
Debt Disclosure [Line Items] |  |  |  |  |  |  |  |  |
Applicable margin |  |  |  | 3.25%pten_ApplicableMarginRate / us-gaap_DebtInstrumentAxis = pten_CreditAgreementMember / us-gaap_RangeAxis = us-gaap_MaximumMember / us-gaap_VariableRateAxis = us-gaap_LondonInterbankOfferedRateLIBORMember |  |  |  |  |
Credit Agreement | Base Rate | Minimum |  |  |  |  |  |  |  |  |
Debt Disclosure [Line Items] |  |  |  |  |  |  |  |  |
Applicable margin |  |  |  | 1.25%pten_ApplicableMarginRate / us-gaap_DebtInstrumentAxis = pten_CreditAgreementMember / us-gaap_RangeAxis = us-gaap_MinimumMember / us-gaap_VariableRateAxis = us-gaap_BaseRateMember |  |  |  |  |
Credit Agreement | Base Rate | Maximum |  |  |  |  |  |  |  |  |
Debt Disclosure [Line Items] |  |  |  |  |  |  |  |  |
Applicable margin |  |  |  | 2.25%pten_ApplicableMarginRate / us-gaap_DebtInstrumentAxis = pten_CreditAgreementMember / us-gaap_RangeAxis = us-gaap_MaximumMember / us-gaap_VariableRateAxis = us-gaap_BaseRateMember |  |  |  |  |
Term Loan Facility |  |  |  |  |  |  |  |  |
Debt Disclosure [Line Items] |  |  |  |  |  |  |  |  |
Line of credit, amount outstanding | 82,500,000 us-gaap_LineOfCredit / us-gaap_LineOfCreditFacilityAxis = pten_TermLoanFacilityMember |  |  |  |  |  |  |  |
Line of credit facility, interest rate | 2.50%us-gaap_LineOfCreditFacilityInterestRateAtPeriodEnd / us-gaap_LineOfCreditFacilityAxis = pten_TermLoanFacilityMember |  |  |  |  |  |  |  |
Term Loan Facility | Credit Agreement |  |  |  |  |  |  |  |  |
Debt Disclosure [Line Items] |  |  |  |  |  |  |  |  |
Current aggregate borrowing capacity |  |  |  | 100,000,000 us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity / us-gaap_DebtInstrumentAxis = pten_CreditAgreementMember / us-gaap_LineOfCreditFacilityAxis = pten_TermLoanFacilityMember |  |  |  |  |
Line of credit facility, frequency of payment and payment terms | The term loan facility provides for a loan of $100 million, which was drawn on December 24, 2012. The term loan facility is payable in quarterly principal installments, which commenced December 27, 2012. The installment amounts vary from 1.25% of the original principal amount for each of the first four quarterly installments, 2.50% of the original principal amount for each of the subsequent eight quarterly installments, 5.00% of the original principal amount for the subsequent four quarterly installments and 13.75% of the original principal amount for the final four quarterly installments. |  |  |  |  |  |  |  |
Line of credit facility, frequency of payments |  |  |  | Quarterly |  |  |  |  |
Commencement date of principal payments |  |  |  | Dec. 27, 2012 |  |  |  |  |
Term Loan Facility | First Four Quarterly Installments | Credit Agreement |  |  |  |  |  |  |  |  |
Debt Disclosure [Line Items] |  |  |  |  |  |  |  |  |
Installment amounts percentage of the original principal amount |  |  |  | 1.25%pten_PrincipalPaymentsPercentage / us-gaap_DebtInstrumentAxis = pten_CreditAgreementMember / pten_EventTimingAxis = pten_GroupOneMember / us-gaap_LineOfCreditFacilityAxis = pten_TermLoanFacilityMember |  |  |  |  |
Term Loan Facility | Subsequent Eight Quarterly Installments | Credit Agreement |  |  |  |  |  |  |  |  |
Debt Disclosure [Line Items] |  |  |  |  |  |  |  |  |
Installment amounts percentage of the original principal amount |  |  |  | 2.50%pten_PrincipalPaymentsPercentage / us-gaap_DebtInstrumentAxis = pten_CreditAgreementMember / pten_EventTimingAxis = pten_GroupTwoMember / us-gaap_LineOfCreditFacilityAxis = pten_TermLoanFacilityMember |  |  |  |  |
Term Loan Facility | Subsequent Four Quarterly Installments | Credit Agreement |  |  |  |  |  |  |  |  |
Debt Disclosure [Line Items] |  |  |  |  |  |  |  |  |
Installment amounts percentage of the original principal amount |  |  |  | 5.00%pten_PrincipalPaymentsPercentage / us-gaap_DebtInstrumentAxis = pten_CreditAgreementMember / pten_EventTimingAxis = pten_GroupThreeMember / us-gaap_LineOfCreditFacilityAxis = pten_TermLoanFacilityMember |  |  |  |  |
Term Loan Facility | Amount For The Final Four Quarterly Installments | Credit Agreement |  |  |  |  |  |  |  |  |
Debt Disclosure [Line Items] |  |  |  |  |  |  |  |  |
Installment amounts percentage of the original principal amount |  |  |  | 13.75%pten_PrincipalPaymentsPercentage / us-gaap_DebtInstrumentAxis = pten_CreditAgreementMember / pten_EventTimingAxis = pten_GroupFourMember / us-gaap_LineOfCreditFacilityAxis = pten_TermLoanFacilityMember |  |  |  |  |
Revolving Credit Facility |  |  |  |  |  |  |  |  |
Debt Disclosure [Line Items] |  |  |  |  |  |  |  |  |
Line of credit, amount outstanding | 303,000,000 us-gaap_LineOfCredit / us-gaap_CreditFacilityAxis = us-gaap_RevolvingCreditFacilityMember |  |  |  |  |  |  |  |
Line of credit facility, weighted average interest rate | 2.65%us-gaap_DebtWeightedAverageInterestRate / us-gaap_CreditFacilityAxis = us-gaap_RevolvingCreditFacilityMember |  |  |  |  |  |  |  |
Revolving Credit Facility | Credit Agreement |  |  |  |  |  |  |  |  |
Debt Disclosure [Line Items] |  |  |  |  |  |  |  |  |
Current aggregate borrowing capacity |  |  |  | 500,000,000 us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity / us-gaap_CreditFacilityAxis = us-gaap_RevolvingCreditFacilityMember / us-gaap_DebtInstrumentAxis = pten_CreditAgreementMember |  |  |  |  |
2010 Credit Agreement |  |  |  |  |  |  |  |  |
Debt Disclosure [Line Items] |  |  |  |  |  |  |  |  |
Credit agreement date |  |  |  |  | Aug. 19, 2010 |  |  |  |
2010 Credit Agreement | Term Loan Facility |  |  |  |  |  |  |  |  |
Debt Disclosure [Line Items] |  |  |  |  |  |  |  |  |
Current aggregate borrowing capacity |  |  |  |  | 100,000,000 us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity / us-gaap_LineOfCreditFacilityAxis = pten_TermLoanFacilityMember / us-gaap_LongtermDebtTypeAxis = pten_CreditFacilityTwentyTenMember |  |  |  |
Line of credit facility, frequency of payment and payment terms |  |  |  |  | The term loan facility was payable in quarterly principal installments commencing November 10, 2010. The installment amounts were scheduled to vary from 1.25% of the original principal amount for each of the first four quarterly installments, 2.50% of the original principal amount for each of the subsequent eight quarterly installments and 5.00% of the original principal amount for the next subsequent three quarterly installments, with the balance due on the maturity date of August 19, 2014. |  |  |  |
Line of credit facility, frequency of payments |  |  |  |  | Quarterly |  |  |  |
Commencement date of principal payments |  |  |  |  | Nov. 10, 2010 |  |  |  |
Debt maturity date |  |  |  |  | Aug. 19, 2014 |  |  |  |
2010 Credit Agreement | Term Loan Facility | First Four Quarterly Installments |  |  |  |  |  |  |  |  |
Debt Disclosure [Line Items] |  |  |  |  |  |  |  |  |
Installment amounts percentage of the original principal amount |  |  |  |  | 1.25%pten_PrincipalPaymentsPercentage / pten_EventTimingAxis = pten_GroupOneMember / us-gaap_LineOfCreditFacilityAxis = pten_TermLoanFacilityMember / us-gaap_LongtermDebtTypeAxis = pten_CreditFacilityTwentyTenMember |  |  |  |
2010 Credit Agreement | Term Loan Facility | Subsequent Eight Quarterly Installments |  |  |  |  |  |  |  |  |
Debt Disclosure [Line Items] |  |  |  |  |  |  |  |  |
Installment amounts percentage of the original principal amount |  |  |  |  | 2.50%pten_PrincipalPaymentsPercentage / pten_EventTimingAxis = pten_GroupTwoMember / us-gaap_LineOfCreditFacilityAxis = pten_TermLoanFacilityMember / us-gaap_LongtermDebtTypeAxis = pten_CreditFacilityTwentyTenMember |  |  |  |
2010 Credit Agreement | Term Loan Facility | Subsequent Four Quarterly Installments |  |  |  |  |  |  |  |  |
Debt Disclosure [Line Items] |  |  |  |  |  |  |  |  |
Installment amounts percentage of the original principal amount |  |  |  |  | 5.00%pten_PrincipalPaymentsPercentage / pten_EventTimingAxis = pten_GroupThreeMember / us-gaap_LineOfCreditFacilityAxis = pten_TermLoanFacilityMember / us-gaap_LongtermDebtTypeAxis = pten_CreditFacilityTwentyTenMember |  |  |  |
2010 Credit Agreement | Revolving Credit Facility |  |  |  |  |  |  |  |  |
Debt Disclosure [Line Items] |  |  |  |  |  |  |  |  |
Credit facility, maximum borrowing capacity |  |  |  |  | 400,000,000 us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity / us-gaap_CreditFacilityAxis = us-gaap_RevolvingCreditFacilityMember / us-gaap_LongtermDebtTypeAxis = pten_CreditFacilityTwentyTenMember |  |  |  |
Letter of Credit | Revolving Credit Facility | Credit Agreement |  |  |  |  |  |  |  |  |
Debt Disclosure [Line Items] |  |  |  |  |  |  |  |  |
Current aggregate borrowing capacity |  |  |  | 150,000,000 us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity / us-gaap_CreditFacilityAxis = us-gaap_RevolvingCreditFacilityMember / us-gaap_DebtInstrumentAxis = pten_CreditAgreementMember / us-gaap_LongtermDebtTypeAxis = us-gaap_LetterOfCreditMember |  |  |  |  |
Swing Line Facility | Revolving Credit Facility | Credit Agreement |  |  |  |  |  |  |  |  |
Debt Disclosure [Line Items] |  |  |  |  |  |  |  |  |
Current aggregate borrowing capacity |  |  |  | 40,000,000 us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity / us-gaap_CreditFacilityAxis = us-gaap_RevolvingCreditFacilityMember / us-gaap_DebtInstrumentAxis = pten_CreditAgreementMember / us-gaap_LongtermDebtTypeAxis = pten_SwinglineLoansMember |  |  |  |  |
4.97% Series A Senior Notes, Due October 5th 2020 |  |  |  |  |  |  |  |  |
Debt Disclosure [Line Items] |  |  |  |  |  |  |  |  |
Debt maturity date |  |  |  |  |  | Oct. 05, 2020 |  |  |
Number of compliance covenants |  |  |  |  |  | 2 pten_NumberOfCovenants / us-gaap_LongtermDebtTypeAxis = pten_SeriesASeniorNotesFourPointNineSevenPercentDueOctoberFiveTwentyTwentyMember |  |  |
Long-term debt, aggregate principal amount |  |  |  |  |  | 300,000,000 us-gaap_DebtInstrumentFaceAmount / us-gaap_LongtermDebtTypeAxis = pten_SeriesASeniorNotesFourPointNineSevenPercentDueOctoberFiveTwentyTwentyMember |  |  |
Debt interest rate |  |  |  |  |  | 4.97%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_LongtermDebtTypeAxis = pten_SeriesASeniorNotesFourPointNineSevenPercentDueOctoberFiveTwentyTwentyMember |  |  |
Notes issuance date |  |  |  |  |  | Oct. 05, 2010 |  |  |
Description of the prepayment terms | Notes are prepayable at the Company’s option, in whole or in part, provided that in the case of a partial prepayment, prepayment must be in an amount not less than 5% of the aggregate principal amount of the notes then outstanding, at any time and from time to time at 100% of the principal amount prepaid, plus accrued and unpaid interest to the prepayment date, plus a “make-whole” premium as specified in the note purchase agreements. The Company must offer to prepay the notes upon the occurrence of any change of control. In addition, the Company must offer to prepay the notes upon the occurrence of certain asset dispositions if the proceeds therefrom are not timely reinvested in productive assets. If any offer to prepay is accepted, the purchase price of each prepaid note is 100% of the principal amount thereof, plus accrued and unpaid interest thereon to the prepayment date. |  |  |  |  |  |  |  |
Description of the acceptance terms | If any offer to prepay is accepted, the purchase price of each prepaid note is 100% of the principal amount thereof, plus accrued and unpaid interest thereon to the prepayment date. |  |  |  |  |  |  |  |
Acceptance terms, percent of principal before accrued and unpaid interest |  |  |  |  |  | 100.00%pten_PercentageOfRepurchasePriceToPrincipalDebtAmount / us-gaap_LongtermDebtTypeAxis = pten_SeriesASeniorNotesFourPointNineSevenPercentDueOctoberFiveTwentyTwentyMember |  |  |
Note purchase agreement, financial covenant description | The Company must not permit its debt to capitalization ratio to exceed 50% at any time. The note purchase agreements generally define the debt to capitalization ratio as the ratio of (a) total borrowed money indebtedness to (b) the sum of such indebtedness plus consolidated net worth, with consolidated net worth determined as of the last day of the most recently ended fiscal quarter. The Company also must not permit the interest coverage ratio as of the last day of a fiscal quarter to be less than 2.50 to 1.00. The note purchase agreements generally define the interest coverage ratio as the ratio of EBITDA for the four prior fiscal quarters to interest charges for the same period. The Company was in compliance with these covenants at December 31, 2014. |  |  |  |  |  |  |  |
4.97% Series A Senior Notes, Due October 5th 2020 | Minimum |  |  |  |  |  |  |  |  |
Debt Disclosure [Line Items] |  |  |  |  |  |  |  |  |
Interest coverage ratio that the Company must exceed on the last day of the fiscal quarter |  |  |  |  |  | 2.50%pten_InterestCoverageRatio / us-gaap_LongtermDebtTypeAxis = pten_SeriesASeniorNotesFourPointNineSevenPercentDueOctoberFiveTwentyTwentyMember / us-gaap_RangeAxis = us-gaap_MinimumMember |  |  |
Prepayment terms, percent of principal before accrued and unpaid interest and "make-whole" premium |  |  |  |  |  | 100.00%us-gaap_DebtInstrumentRedemptionPricePercentage / us-gaap_LongtermDebtTypeAxis = pten_SeriesASeniorNotesFourPointNineSevenPercentDueOctoberFiveTwentyTwentyMember / us-gaap_RangeAxis = us-gaap_MinimumMember |  |  |
4.97% Series A Senior Notes, Due October 5th 2020 | Maximum |  |  |  |  |  |  |  |  |
Debt Disclosure [Line Items] |  |  |  |  |  |  |  |  |
Debt to capitalization ratio, percentage the Company must not exceed at any time |  |  |  |  |  | 50.00%pten_ConsolidatedDebtAsPercentageOfCapitalization / us-gaap_LongtermDebtTypeAxis = pten_SeriesASeniorNotesFourPointNineSevenPercentDueOctoberFiveTwentyTwentyMember / us-gaap_RangeAxis = us-gaap_MaximumMember |  |  |
4.97% Series A Senior Notes, Due October 5th 2020 | Credit Agreement |  |  |  |  |  |  |  |  |
Debt Disclosure [Line Items] |  |  |  |  |  |  |  |  |
Debt issuance costs |  |  |  |  |  |  | 10,800,000 us-gaap_PaymentsOfDebtIssuanceCosts / us-gaap_DebtInstrumentAxis = pten_CreditAgreementMember / us-gaap_LongtermDebtTypeAxis = pten_SeriesASeniorNotesFourPointNineSevenPercentDueOctoberFiveTwentyTwentyMember |  |
4.97% Series A Senior Notes, Due October 5th 2020 | Semi Annual Payment, First Payment |  |  |  |  |  |  |  |  |
Debt Disclosure [Line Items] |  |  |  |  |  |  |  |  |
Interest pay date | April 5 |  |  |  |  |  |  |  |
4.97% Series A Senior Notes, Due October 5th 2020 | Semi Annual Payment, Second Payment |  |  |  |  |  |  |  |  |
Debt Disclosure [Line Items] |  |  |  |  |  |  |  |  |
Interest pay date | October 5 |  |  |  |  |  |  |  |
4.27% Series B Senior Notes, Due June 14th 2022 |  |  |  |  |  |  |  |  |
Debt Disclosure [Line Items] |  |  |  |  |  |  |  |  |
Debt maturity date |  |  |  |  |  |  |  | Jun. 14, 2022 |
Number of compliance covenants |  |  |  |  |  |  |  | 2 pten_NumberOfCovenants / us-gaap_LongtermDebtTypeAxis = pten_SeriesBSeniorNotesFourPointTwoSevenPercentDueJuneFourteenTwentyTwentyTwoMember |
Long-term debt, aggregate principal amount |  |  |  |  |  |  |  | 300,000,000 us-gaap_DebtInstrumentFaceAmount / us-gaap_LongtermDebtTypeAxis = pten_SeriesBSeniorNotesFourPointTwoSevenPercentDueJuneFourteenTwentyTwentyTwoMember |
Debt interest rate |  |  |  |  |  |  |  | 4.27%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_LongtermDebtTypeAxis = pten_SeriesBSeniorNotesFourPointTwoSevenPercentDueJuneFourteenTwentyTwentyTwoMember |
Notes issuance date |  |  |  |  |  |  |  | Jun. 14, 2012 |
Description of the prepayment terms | Notes are prepayable at the Company’s option, in whole or in part, provided that in the case of a partial prepayment, prepayment must be in an amount not less than 5% of the aggregate principal amount of the notes then outstanding, at any time and from time to time at 100% of the principal amount prepaid, plus accrued and unpaid interest to the prepayment date, plus a “make-whole” premium as specified in the note purchase agreements. The Company must offer to prepay the notes upon the occurrence of any change of control. In addition, the Company must offer to prepay the notes upon the occurrence of certain asset dispositions if the proceeds therefrom are not timely reinvested in productive assets. If any offer to prepay is accepted, the purchase price of each prepaid note is 100% of the principal amount thereof, plus accrued and unpaid interest thereon to the prepayment date. |  |  |  |  |  |  |  |
Description of the acceptance terms | If any offer to prepay is accepted, the purchase price of each prepaid note is 100% of the principal amount thereof, plus accrued and unpaid interest thereon to the prepayment date. |  |  |  |  |  |  |  |
Acceptance terms, percent of principal before accrued and unpaid interest |  |  |  |  |  |  |  | 100.00%pten_PercentageOfRepurchasePriceToPrincipalDebtAmount / us-gaap_LongtermDebtTypeAxis = pten_SeriesBSeniorNotesFourPointTwoSevenPercentDueJuneFourteenTwentyTwentyTwoMember |
Note purchase agreement, financial covenant description | The Company must not permit its debt to capitalization ratio to exceed 50% at any time. The note purchase agreements generally define the debt to capitalization ratio as the ratio of (a) total borrowed money indebtedness to (b) the sum of such indebtedness plus consolidated net worth, with consolidated net worth determined as of the last day of the most recently ended fiscal quarter. The Company also must not permit the interest coverage ratio as of the last day of a fiscal quarter to be less than 2.50 to 1.00. The note purchase agreements generally define the interest coverage ratio as the ratio of EBITDA for the four prior fiscal quarters to interest charges for the same period. The Company was in compliance with these covenants at December 31, 2014. |  |  |  |  |  |  |  |
4.27% Series B Senior Notes, Due June 14th 2022 | Minimum |  |  |  |  |  |  |  |  |
Debt Disclosure [Line Items] |  |  |  |  |  |  |  |  |
Interest coverage ratio that the Company must exceed on the last day of the fiscal quarter |  |  |  |  |  |  |  | 2.50%pten_InterestCoverageRatio / us-gaap_LongtermDebtTypeAxis = pten_SeriesBSeniorNotesFourPointTwoSevenPercentDueJuneFourteenTwentyTwentyTwoMember / us-gaap_RangeAxis = us-gaap_MinimumMember |
Prepayment terms, percent of principal before accrued and unpaid interest and "make-whole" premium |  |  |  |  |  |  |  | 100.00%us-gaap_DebtInstrumentRedemptionPricePercentage / us-gaap_LongtermDebtTypeAxis = pten_SeriesBSeniorNotesFourPointTwoSevenPercentDueJuneFourteenTwentyTwentyTwoMember / us-gaap_RangeAxis = us-gaap_MinimumMember |
4.27% Series B Senior Notes, Due June 14th 2022 | Maximum |  |  |  |  |  |  |  |  |
Debt Disclosure [Line Items] |  |  |  |  |  |  |  |  |
Debt to capitalization ratio, percentage the Company must not exceed at any time |  |  |  |  |  |  |  | 50.00%pten_ConsolidatedDebtAsPercentageOfCapitalization / us-gaap_LongtermDebtTypeAxis = pten_SeriesBSeniorNotesFourPointTwoSevenPercentDueJuneFourteenTwentyTwentyTwoMember / us-gaap_RangeAxis = us-gaap_MaximumMember |
4.27% Series B Senior Notes, Due June 14th 2022 | Credit Agreement |  |  |  |  |  |  |  |  |
Debt Disclosure [Line Items] |  |  |  |  |  |  |  |  |
Debt issuance costs |  |  | 7,600,000 us-gaap_PaymentsOfDebtIssuanceCosts / us-gaap_DebtInstrumentAxis = pten_CreditAgreementMember / us-gaap_LongtermDebtTypeAxis = pten_SeriesBSeniorNotesFourPointTwoSevenPercentDueJuneFourteenTwentyTwentyTwoMember |  |  |  |  |  |
4.27% Series B Senior Notes, Due June 14th 2022 | Semi Annual Payment, First Payment |  |  |  |  |  |  |  |  |
Debt Disclosure [Line Items] |  |  |  |  |  |  |  |  |
Interest pay date | April 5 |  |  |  |  |  |  |  |
4.27% Series B Senior Notes, Due June 14th 2022 | Semi Annual Payment, Second Payment |  |  |  |  |  |  |  |  |
Debt Disclosure [Line Items] |  |  |  |  |  |  |  |  |
Interest pay date | October 5 |  |  |  |  |  |  |  |
Corporate Debt Securities | 2010 Credit Agreement |  |  |  |  |  |  |  |  |
Debt Disclosure [Line Items] |  |  |  |  |  |  |  |  |
Interest expense on debt extinguishment |  |  | $ 978,000 pten_InterestExpenseOnDebtExtinguishment / us-gaap_DebtInstrumentAxis = pten_TwoThousandTenCreditAgreementMember / us-gaap_LongtermDebtTypeAxis = us-gaap_CorporateDebtSecuritiesMember |  |  |  |  |  |

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- Definition Description of minimum financial levels (for example, tangible net worth and working capital) and achievement of certain financial ratios (for example, working capital ratio and debt service coverage ratio), and adherence to certain clauses which generally require or restrict certain actions (for example, entering into a debt arrangement with equal or greater seniority, and selling or discontinuing a certain business segment or material subsidiary) to be in compliance with the covenant clauses of the debt agreement. May also include a discussion of the adverse consequences that would result if the entity violates or fails to satisfy the covenants. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 22 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 470 -Section 50 -Paragraph 3 -Subparagraph (g) -URI http://asc.fasb.org/extlink&oid=6479336&loc=d3e64711-112823 + Details
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- Definition Date the debt agreement requires the first payment to be made, in CCYY-MM-DD format. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 22 -Article 5 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 470 -Section 50 -Paragraph 3 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=6479336&loc=d3e64711-112823 + Details
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- Definition Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 22 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(2)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
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- Definition Percentage price of original principal amount of debt at which debt can be redeemed by the issuer. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 470 -Section 50 -Paragraph 3 -Subparagraph e -URI http://asc.fasb.org/extlink&oid=6479336&loc=d3e64711-112823 + Details
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- Definition The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.16) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 19, 20, 22 -Article 5 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03.16) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910 + Details
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- Definition Amount of current borrowing capacity under the credit facility considering any current restrictions on the amount that could be borrowed (for example, borrowings may be limited by the amount of current assets), but without considering any amounts currently outstanding under the facility. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.19(b),22(b)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 19, 22 -Article 5 + Details
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- Definition Date the credit facility first became available, in CCYY-MM-DD format. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.19(b),22(b)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 19, 22 -Article 5 + Details
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- Definition The effective interest rate at the end of the reporting period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.19(b),22(b)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 19, 22 -Article 5 + Details
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- Definition Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.19(b),22(b)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 19, 22 -Article 5 + Details
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- Definition The cash outflow paid to third parties in connection with debt origination, which will be amortized over the remaining maturity period of the associated long-term debt. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 15 -Subparagraph (e) -URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3291-108585 + Details
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