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Concentrations of Credit Risk - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified | 12 Months Ended
--- | ---
Dec. 31, 2011 | Dec. 31, 2010 | Dec. 31, 2009
Concentration Risk [Line Items] |  |  |
Provision for bad debts | $ 0 | $ (2,000) | $ 3,810

X
- Definition Provision For Reduction Of Doubtful Accounts + References No definition available. + Details
Name: | pten_ProvisionForReductionOfDoubtfulAccounts
Namespace Prefix: | pten_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

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- Details
Name: | us-gaap_ConcentrationRiskLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration