2.2.0.7 false CONDENSED CONSOLIDATED BALANCE SHEETS (USD $) 103 - Statement - CONDENSED CONSOLIDATED BALANCE SHEETS true false In Thousands false false 1 USD false false iso4217_USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 iso4217_USD_per_shares Divide http://www.xbrl.org/2003/iso4217 USD iso4217 http://www.xbrl.org/2003/instance shares 0 shares Standard http://www.xbrl.org/2003/instance shares 0 $ false 2 USD false false iso4217_USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 iso4217_USD_per_shares Divide http://www.xbrl.org/2003/iso4217 USD iso4217 http://www.xbrl.org/2003/instance shares 0 shares Standard http://www.xbrl.org/2003/instance shares 0 $ 6 Current assets: 4 us-gaap_AssetsCurrentAbstract us-gaap true na duration No definition available. false false false false false true false false false false false false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 7 Cash and cash equivalents 5 us-gaap_CashAndCashEquivalentsAtCarryingValue us-gaap true debit instant No definition available. false false false false false false false false false false false false 1 true true false false 1133000 1133 false false false 2 true true false false 1140000 1140 false false false xbrli:monetaryItemType monetary Includes currency on hand as well as demand deposits with banks or financial institutions. It also includes other kinds of accounts that have the general characteristics of demand deposits in that the Entity may deposit additional funds at any time and also effectively may withdraw funds at any time without prior notice or penalty. Cash equivalents, excluding items classified as marketable securities, include short-term, highly liquid investments that are both readily convertible to known amounts of cash, and so near their maturity that they present minimal risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three years ago does not become a cash equivalent when its remaining maturity is three months. Compensating balance arrangements that do not legally restrict the withdrawal or usage of cash amounts may be reported as Cash and Cash Equivalents, while legally restricted deposits held as compensating balances against borrowing arrangements, contracts entered into with others, or company statements of intention with regard to particular deposits should not be reported as cash and cash equivalents. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 7, 26 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 8, 9 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 7 -Footnote 1 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 1 -Article 5 false 8 Restricted cash 5 us-gaap_RestrictedCashAndCashEquivalentsAtCarryingValue us-gaap true debit instant No definition available. false false false false false false false false false false false false 1 false true false false 20000 20 false false false 2 false true false false 20000 20 false false false xbrli:monetaryItemType monetary The carrying amounts of cash and cash equivalent items which are restricted as to withdrawal or usage. Restrictions may include legally restricted deposits held as compensating balances against short-term borrowing arrangements, contracts entered into with others, or entity statements of intention with regard to particular deposits; however, time deposits and short-term certificates of deposit are not generally included in legally restricted deposits. Excludes compensating balance arrangements that are not agreements which legally restrict the use of cash amounts shown on the balance sheet. For a classified balance sheet represents the current portion only (the noncurrent portion has a separate concept); there is a separate and distinct element for unclassified presentations. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 1 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Audit and Accounting Guide (AAG) -Number AAG-BRD -Chapter 4 -Paragraph 80 -Subparagraph Exhibit 4-8, 3 -IssueDate 2006-05-01 false 9 Accounts receivable, net of allowance for doubtful accounts of $5,184 at September 30, 2010 and $5,186 at December 31, 2009 5 us-gaap_AccountsReceivableNetCurrent us-gaap true debit instant No definition available. false false false false false false false false false false false false 1 false true false false 107040000 107040 false false false 2 false true false false 74382000 74382 false false false xbrli:monetaryItemType monetary Amount due from customers or clients, within one year of the balance sheet date (or the normal operating cycle, whichever is longer), for goods or services (including trade receivables) that have been delivered or sold in the normal course of business, reduced to the estimated net realizable fair value by an allowance established by the entity of the amount it deems uncertain of collection. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 3 -Subparagraph a(1) -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 4 -Article 5 false 10 Materials and supplies 5 us-gaap_InventoryRawMaterialsAndSupplies us-gaap true debit instant No definition available. false false false false false false false false false false false false 1 false true false false 6568000 6568 false false false 2 false true false false 6914000 6914 false false false xbrli:monetaryItemType monetary Aggregated amount of unprocessed materials to be used in manufacturing or production process and supplies that will be consumed. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 6 -Subparagraph a -Article 5 false 11 Derivative assets (Note 10) 5 us-gaap_DerivativeAssetsCurrent us-gaap true debit instant No definition available. false false false false false false false false false false false false 1 false true false false 19400000 19400 false false false 2 false true false false 9945000 9945 false false false xbrli:monetaryItemType monetary Fair values as of the balance sheet date for all assets resulting from contracts that meet the criteria of being accounted for as derivative instruments and which are expected to be converted into cash or otherwise disposed of within a year or the normal operating cycle, if longer, net of the effects of master netting arrangements. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 133 -Paragraph 4, 17 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 107 -Paragraph 10 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 43 -Chapter 3 -Section A -Paragraph 4 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name FASB Staff Position (FSP) -Number FIN39-1 -Paragraph 10A, 10B false 12 Income tax receivable 5 us-gaap_IncomeTaxesReceivable us-gaap true debit instant No definition available. false false false false false false false false false false false false 1 false true false false 5944000 5944 false false false 2 false true false false 15236000 15236 false false false xbrli:monetaryItemType monetary Carrying amount due within one year of the balance sheet date (or one operating cycle, if longer) from tax authorities as of the balance sheet date representing refunds of overpayments or recoveries based on agreed-upon resolutions of disputes. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 5 -Subparagraph c -Article 7 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 3 -Subparagraph a -Article 5 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 109 -Section Appendix E -Paragraph 289 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 10 -Article 9 false 13 Deferred tax asset 5 us-gaap_DeferredTaxAssetsNetCurrent us-gaap true debit instant No definition available. false false false false false false false false false false false false 1 false true false false 12484000 12484 false false false 2 false true false false 14423000 14423 false false false xbrli:monetaryItemType monetary The current portion of the aggregate tax effects as of the balance sheet date of all future tax deductions arising from temporary differences between tax basis and generally accepted accounting principles basis recognition of assets, liabilities, revenues and expenses, which can only be deducted for tax purposes when permitted under enacted tax laws; after deducting the allocated valuation allowance, if any, to reduce such amount to net realizable value. Deferred tax liabilities and assets shall be classified as current or noncurrent based on the classification of the related asset or liability for financial reporting. A deferred tax liability or asset that is not related to an asset or liability for financial reporting, including deferred tax assets related to carryforwards, shall be classified according to the expected reversal date of the temporary difference. An unrecognized tax benefit that is directly related to a position taken in a tax year that results in a net operating loss carryforward should be presented as a reduction of the related deferred tax asset. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 109 -Paragraph 41, 42, 43 false 14 Prepaid expenses and other 5 unt_PrepaidExpenseAndOtherAssetsCurrent unt false debit instant Includes the sum of the amounts paid in advance for costs that will be expensed with the passage of time or the occurrence of... false false false false false false false false false false false false 1 false true false false 5571000 5571 false false false 2 false true false false 6035000 6035 false false false xbrli:monetaryItemType monetary Includes the sum of the amounts paid in advance for costs that will be expensed with the passage of time or the occurrence of a triggering event, interest earned but not received, value added taxes due either from customers arising from sales on credit terms, or as previously overpaid to tax authorities, fair values for all assets resulting from contracts that meet the criteria of being accounted for as derivative instruments and carrying amounts due as of the balance sheet date from parties or arising from transactions not otherwise specified in the taxonomy. All amounts in this caption are expected to be collected within one year. No authoritative reference available. false 15 Total current assets 5 us-gaap_AssetsCurrent us-gaap true debit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false 158160000 158160 false false false 2 false true false false 128095000 128095 false false false xbrli:monetaryItemType monetary Sum of the carrying amounts as of the balance sheet date of all assets that are expected to be realized in cash, sold, or consumed within one year (or the normal operating cycle, if longer). Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 9 -Article 5 true 16 Property and equipment: 4 us-gaap_PropertyPlantAndEquipmentNetAbstract us-gaap true na duration No definition available. false false false false false true false false false false false false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 17 Drilling equipment 5 us-gaap_CapitalizedCostsSupportEquipmentAndFacilities us-gaap true debit instant No definition available. false false false false false false false false false false false false 1 false true false false 1255107000 1255107 false false false 2 false true false false 1217361000 1217361 false false false xbrli:monetaryItemType monetary Capitalized costs incurred for support equipment and facilities used in oil and gas producing activities (such as seismic equipment, drilling equipment, construction and grading equipment, vehicles, repair shops, warehouses, supply points, camps, and division, district, or field offices). Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 19 -Paragraph 59M, 59N false 18 Oil and natural gas properties using the full cost method: 5 unt_OilGasPropertyFullCostMethodGrossAbstract unt false na duration Oil and Gas Property - Full Cost Method, Gross [Abstract] false false false false false true false false false false false false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false xbrli:stringItemType string Oil and Gas Property - Full Cost Method, Gross [Abstract] false 19 Proved properties 6 unt_OilAndNaturalGasPropertiesFullCostMethodSubjectToAmortization unt false debit instant Oil and natural gas properties-full cost method, subject to amortization. false false false false false false false false false false false false 1 false true false false 2591644000 2591644 false false false 2 false true false false 2309193000 2309193 false false false xbrli:monetaryItemType monetary Oil and natural gas properties-full cost method, subject to amortization. No authoritative reference available. false 20 Undeveloped leasehold not being amortized 6 unt_OilAndNaturalGasPropertiesFullCostMethodNotSubjectToAmortization unt false debit instant Oil and natural gas properties-full cost method, not subject to amortization. false false false false false false false false false false false false 1 false true false false 194774000 194774 false false false 2 false true false false 140129000 140129 false false false xbrli:monetaryItemType monetary Oil and natural gas properties-full cost method, not subject to amortization. No authoritative reference available. false 21 Gas gathering and processing equipment 5 unt_NaturalGasGatheringSystemsAndTreatingPlants unt false debit instant Natural gas gathering systems and treating plants. false false false false false false false false false false false false 1 false true false false 191943000 191943 false false false 2 false true false false 172549000 172549 false false false xbrli:monetaryItemType monetary Natural gas gathering systems and treating plants. No authoritative reference available. false 22 Transportation equipment 5 us-gaap_MachineryAndEquipmentGross us-gaap true debit instant No definition available. false false false false false false false false false false false false 1 false true false false 32067000 32067 false false false 2 false true false false 30726000 30726 false false false xbrli:monetaryItemType monetary Carrying amount as of the balance sheet date of long-lived, depreciable asset used in production process to produce goods and services. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 12 -Paragraph 5 false 23 Other 5 us-gaap_PropertyPlantAndEquipmentOther us-gaap true debit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 24831000 24831 false false false 2 false true false false 22747000 22747 false false false xbrli:monetaryItemType monetary This element represents capitalized assets classified as property, plant and equipment not otherwise defined in the taxonomy. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 12 -Paragraph 5 false 24 Property, Plant and Equipment, Gross, Total 5 us-gaap_PropertyPlantAndEquipmentGross us-gaap true debit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false 4290366000 4290366 false false false 2 false true false false 3892705000 3892705 false false false xbrli:monetaryItemType monetary Carrying amount at the balance sheet date for long-lived physical assets used in the normal conduct of business and not intended for resale. This can include land, physical structures, machinery, vehicles, furniture, computer equipment, construction in progress, and similar items. Amount does not include depreciation. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 12 -Paragraph 5 true 25 Less accumulated depreciation, depletion, amortization and impairment 5 us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment us-gaap true credit instant No definition available. false false false false false false false false false false false false 1 false true false false 1992520000 1992520 false false false 2 false true false false 1879112000 1879112 false false false xbrli:monetaryItemType monetary The cumulative amount of depreciation, depletion and amortization (related to property, plant and equipment, but not including land) that has been recognized in the income statement. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 12 -Paragraph 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 12 -Paragraph 5 -Subparagraph c Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 14 -Article 5 false 26 Net property and equipment 5 us-gaap_PropertyPlantAndEquipmentNet us-gaap true debit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false 2297846000 2297846 false false false 2 false true false false 2013593000 2013593 false false false xbrli:monetaryItemType monetary Tangible assets that are held by an entity for use in the production or supply of goods and services, for rental to others, or for administrative purposes and that are expected to provide economic benefit for more than one year; net of accumulated depreciation. Examples include land, buildings, and production equipment. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 13 -Subparagraph a -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 12 -Paragraph 5 -Subparagraph b, c Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 8 -Article 7 true 27 Goodwill 4 us-gaap_Goodwill us-gaap true debit instant No definition available. false false false false false false false false false false false false 1 false true false false 62808000 62808 false false false 2 false true false false 62808000 62808 false false false xbrli:monetaryItemType monetary Carrying amount as of the balance sheet date, which is the cumulative amount paid, adjusted for any amortization recognized prior to adoption of FAS 142 and for any impairment charges, in excess of the fair value of net assets acquired in one or more business combination transactions. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 142 -Paragraph 43 false 28 Other intangible assets, net 4 us-gaap_IntangibleAssetsNetExcludingGoodwill us-gaap true debit instant No definition available. false false false false false false false false false false false false 1 false true false false 3303000 3303 false false false 2 false true false false 5633000 5633 false false false xbrli:monetaryItemType monetary Sum of the carrying amounts of all intangible assets, excluding goodwill, as of the balance sheet date, net of accumulated amortization and impairment charges. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 142 -Paragraph 42, 45 false 29 Non-current derivative assets (Note 10) 4 us-gaap_DerivativeAssetsNoncurrent us-gaap true debit instant No definition available. false false false false false false false false false false false false 1 false true false false 5694000 5694 false false false 2 false true false false 0 0 false false false xbrli:monetaryItemType monetary Fair values as of the balance sheet date of all assets resulting from contracts that meet the criteria of being accounted for as derivative instruments which are expected to exist longer than one year or beyond the normal operating cycle, if longer, net of the effects of master netting arrangements. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 133 -Paragraph 4, 17 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 107 -Paragraph 10 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 43 -Chapter 3 -Section A -Paragraph 4 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name FASB Staff Position (FSP) -Number FIN39-1 -Paragraph 10A, 10B false 30 Other assets 4 us-gaap_OtherAssetsNoncurrent us-gaap true debit instant No definition available. false false false false false false false false false false false false 1 false true false false 17074000 17074 false false false 2 false true false false 18270000 18270 false false false xbrli:monetaryItemType monetary Aggregate carrying amount, as of the balance sheet date, of noncurrent assets not separately disclosed in the balance sheet due to materiality considerations. Noncurrent assets are expected to be realized or consumed after one year (or the normal operating cycle, if longer). Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 17 -Article 5 false 31 Total assets 4 us-gaap_Assets us-gaap true debit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false 2544885000 2544885 false false false 2 false true false false 2228399000 2228399 false false false xbrli:monetaryItemType monetary Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Concepts (CON) -Number 6 -Paragraph 25 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 18 -Article 5 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 12 -Article 7 true 33 Current liabilities: 4 us-gaap_LiabilitiesCurrentAbstract us-gaap true na duration No definition available. false false false false false true false false false false false false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 34 Accounts payable 5 us-gaap_AccountsPayableCurrent us-gaap true credit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 65681000 65681 false false false 2 false true false false 55880000 55880 false false false xbrli:monetaryItemType monetary Carrying value as of the balance sheet date of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer). Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 19 -Subparagraph a -Article 5 false 35 Accrued liabilities (Note 5) 5 us-gaap_AccruedLiabilitiesCurrent us-gaap true credit instant No definition available. false false false false false false false false false false false false 1 false true false false 42387000 42387 false false false 2 false true false false 34571000 34571 false false false xbrli:monetaryItemType monetary Carrying value as of the balance sheet date of obligations incurred and payable, pertaining to costs that are statutory in nature, are incurred on contractual obligations, or accumulate over time and for which invoices have not yet been received or will not be rendered. Examples include taxes, interest, rent and utilities. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer). Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 20 -Article 5 false 36 Contract advances 5 us-gaap_CustomerAdvancesCurrent us-gaap true credit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 3844000 3844 false false false 2 false true false false 3124000 3124 false false false xbrli:monetaryItemType monetary The current portion, due within one year or the normal operating cycle, if longer, of prepayments received from customers for goods or services to be provided in the future. No authoritative reference available. false 37 Derivative liabilities (Note 10) 5 us-gaap_DerivativeLiabilitiesCurrent us-gaap true credit instant No definition available. false false false false false false false false false false false false 1 false true false false 1278000 1278 false false false 2 false true false false 2230000 2230 false false false xbrli:monetaryItemType monetary Fair values as of the balance sheet date of all liabilities resulting from contracts that meet the criteria of being accounted for as derivative instruments, and which are expected to be extinguished or otherwise disposed of within a year or the normal operating cycle, if longer, net of the effects of master netting arrangements. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 43 -Chapter 3 -Section A -Paragraph 7 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name FASB Staff Position (FSP) -Number FIN39-1 -Paragraph 10A, 10B Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 133 -Paragraph 4, 17 false 38 Other liabilities (Note 6) 5 us-gaap_OtherLiabilitiesCurrent us-gaap true credit instant No definition available. false false false false false false false false false false false false 1 false true false false 9490000 9490 false false false 2 false true false false 9342000 9342 false false false xbrli:monetaryItemType monetary Aggregate carrying amount, as of the balance sheet date, of current obligations not separately disclosed in the balance sheet due to materiality considerations. Current liabilities are expected to be paid within one year (or the normal operating cycle, if longer). Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 20 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 43 -Chapter 3 -Section A -Paragraph 8 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 6 -Paragraph 15 false 39 Total current liabilities 5 us-gaap_LiabilitiesCurrent us-gaap true credit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false 122680000 122680 false false false 2 false true false false 105147000 105147 false false false xbrli:monetaryItemType monetary Total obligations incurred as part of normal operations that are expected to be paid during the following twelve months or within one business cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 21 -Article 5 true 40 Long-term debt (Note 6) 4 us-gaap_LongTermDebtNoncurrent us-gaap true credit instant No definition available. false false false false false false false false false false false false 1 false true false false 135000000 135000 false false false 2 false true false false 30000000 30000 false false false xbrli:monetaryItemType monetary Sum of the carrying values as of the balance sheet date of all long-term debt, which is debt initially having maturities due after one year from the balance sheet date or beyond the operating cycle, if longer, but excluding the portions thereof scheduled to be repaid within one year (current maturities) or the normal operating cycle, if longer, and after deducting unamortized discount or premiums, if any. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 22 -Article 5 false 41 Long-term derivative liabilities (Note 10) 4 us-gaap_DerivativeLiabilitiesNoncurrent us-gaap true credit instant No definition available. false false false false false false false false false false false false 1 false true false false 3392000 3392 false false false 2 false true false false 1142000 1142 false false false xbrli:monetaryItemType monetary Fair values as of the balance sheet date of all liabilities resulting from contracts that meet the criteria of being accounted for as derivative instruments, and which are expected to be extinguished or otherwise disposed of after one year or beyond the normal operating cycle, if longer, net of the effects of master netting arrangements. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 133 -Paragraph 4, 17 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 43 -Chapter 3 -Section A -Paragraph 7 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 107 -Paragraph 10 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name FASB Staff Position (FSP) -Number FIN39-1 -Paragraph 10A, 10B false 42 Other long-term liabilities (Note 6) 4 us-gaap_OtherLiabilitiesNoncurrent us-gaap true credit instant No definition available. false false false false false false false false false false false false 1 false true false false 87382000 87382 false false false 2 false true false false 79984000 79984 false false false xbrli:monetaryItemType monetary Aggregate carrying amount, as of the balance sheet date, of noncurrent obligations not separately disclosed in the balance sheet due to materiality considerations. Noncurrent liabilities are expected to be paid after one year (or the normal operating cycle, if longer). Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 24 -Article 5 false 43 Deferred income taxes 4 us-gaap_DeferredTaxLiabilitiesNoncurrent us-gaap true credit instant No definition available. false false false false false false false false false false false false 1 false true false false 513563000 513563 false false false 2 false true false false 446316000 446316 false false false xbrli:monetaryItemType monetary Represents the noncurrent portion of deferred tax liabilities, which result from applying the applicable tax rate to net taxable temporary differences pertaining to each jurisdiction to which the entity is obligated to pay income tax. A noncurrent taxable temporary difference is a difference between the tax basis and the carrying amount of a noncurrent asset or liability in the financial statements prepared in accordance with generally accepted accounting principles. In a classified statement of financial position, an enterprise shall separate deferred tax liabilities and assets into a current amount and a noncurrent amount. Deferred tax liabilities and assets shall be classified as current or noncurrent based on the classification of the related asset or liability for financial reporting. A deferred tax liability or asset that is not related to an asset or liability for financial reporting, including deferred tax assets related to carryforwards, shall be classified according to the expected reversal date of the temporary difference. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 109 -Paragraph 41, 42 false 44 Shareholders' equity: 4 us-gaap_StockholdersEquityAbstract us-gaap true na duration No definition available. false false false false false true false false false false false false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 45 Preferred stock, $1.00 par value, 5,000,000 shares authorized, none issued 5 us-gaap_PreferredStockValue us-gaap true credit instant No definition available. false false false false false false false false false false false false 1 false true false false 0 0 false false false 2 false true false false 0 0 false false false xbrli:monetaryItemType monetary Dollar value of issued nonredeemable preferred stock (or preferred stock redeemable solely at the option of the issuer) whether issued at par value, no par or stated value. This item includes treasury stock repurchased by the entity. Note: elements for number of nonredeemable preferred shares, par value and other disclosure concepts are in another section within stockholders' equity. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 129 -Paragraph 2, 3, 4, 5, 6, 7, 8 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 12 -Paragraph 10 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Article 3 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 29 -Article 5 false 46 Common stock, $.20 par value, 175,000,000 shares authorized, 47,899,300 and 47,530,669 shares issued, respectively 5 us-gaap_CommonStockValue us-gaap true credit instant No definition available. false false false false false false false false false false false false 1 false true false false 9490000 9490 false false false 2 false true false false 9405000 9405 false false false xbrli:monetaryItemType monetary Dollar value of issued common stock whether issued at par value, no par or stated value. This item includes treasury stock repurchased by the entity. Note: elements for number of common shares, par value and other disclosure concepts are in another section within stockholders' equity. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 30 -Article 5 false 47 Capital in excess of par value 5 us-gaap_AdditionalPaidInCapital us-gaap true credit instant No definition available. false false false false false false false false false false false false 1 false true false false 390303000 390303 false false false 2 false true false false 383957000 383957 false false false xbrli:monetaryItemType monetary Excess of issue price over par or stated value of the entity's capital stock and amounts received from other transactions involving the entity's stock or stockholders. Includes adjustments to additional paid in capital. Some examples of such adjustments include recording the issuance of debt with a beneficial conversion feature and certain tax consequences of equity instruments awarded to employees. Use this element for the aggregate amount of APIC associated with common AND preferred stock. For APIC associated with only common stock, use the element Additional Paid In Capital, Common Stock. For APIC associated with only preferred stock, use the element Additional Paid In Capital, Preferred Stock. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 31 -Article 5 false 48 Accumulated other comprehensive income 5 us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax us-gaap true credit instant No definition available. false false false false false false false false false false false false 1 false true false false 12266000 12266 false false false 2 false true false false 4458000 4458 false false false xbrli:monetaryItemType monetary Accumulated change in equity from transactions and other events and circumstances from non-owner sources, net of tax effect, at fiscal year-end. Excludes Net Income (Loss), and accumulated changes in equity from transactions resulting from investments by owners and distributions to owners. Includes foreign currency translation items, certain pension adjustments, and unrealized gains and losses on certain investments in debt and equity securities as well as changes in the fair value of derivatives related to the effective portion of a designated cash flow hedge. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Article 3 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 12 -Paragraph 10 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 130 -Paragraph 14, 17, 26 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 31 -Article 5 false 49 Retained earnings 5 us-gaap_RetainedEarningsAccumulatedDeficit us-gaap true credit instant No definition available. false false false false false false false false false false false false 1 false true false false 1270809000 1270809 false false false 2 false true false false 1167990000 1167990 false false false xbrli:monetaryItemType monetary The cumulative amount of the reporting entity's undistributed earnings or deficit. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 12 -Paragraph 10 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 31 -Article 5 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Article 3 false 50 Total shareholders' equity 5 us-gaap_StockholdersEquity us-gaap true credit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false 1682868000 1682868 false false false 2 false true false false 1565810000 1565810 false false false xbrli:monetaryItemType monetary Total of all Stockholders' Equity (deficit) items, net of receivables from officers, directors owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph A3 -Appendix A Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 4 -Section E Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 29, 30, 31 -Article 5 true 51 Total liabilities and shareholders' equity 4 us-gaap_LiabilitiesAndStockholdersEquity us-gaap true credit instant No definition available. false false false false false false false false false false false totallabel false 1 true true false false 2544885000 2544885 false false false 2 true true false false 2228399000 2228399 false false false xbrli:monetaryItemType monetary Total of all Liabilities and Stockholders' Equity items. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 32 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 25 -Article 7 true 2 45 false Thousands UnKnown UnKnown false true