XML 28 R10.htm IDEA: XBRL DOCUMENT
v3.6.0.2

ACCOUNTING POLICIES | 12 Months Ended
--- | ---
Dec. 31, 2016
ACCOUNTING POLICIES |
ACCOUNTING POLICIES | NOTE B – ACCOUNTING POLICIES Cash, Cash Equivalents, and Short‑Term Investments: Short‑term investments that have a maturity of ninety days or less when purchased are considered cash equivalents. Variable rate demand notes are classified as cash equivalents, as the investments may be redeemed on a daily basis with the original issuer. Short‑term investments consist of FDIC‑insured certificates of deposit with original maturities greater than ninety days and remaining maturities less than one year. Interest and dividends related to cash, cash equivalents, and short‑term investments are included in interest and dividend income. Restricted Cash: Cash that is pledged as collateral, primarily for the Company’s outstanding letters of credit, is classified as restricted. The Company’s letters of credit are primarily issued in support of certain workers’ compensation and third‑party casualty claims liabilities in various states in which the Company is self‑insured. The restricted cash is classified consistent with the classification of the liabilities to which it relates and in accordance with the duration of the letters of credit. Restricted cash consisted of cash deposits at December 31, 2016 and 2015. Changes in the amount of restricted funds are reflected as financing activities in the consolidated statements of cash flows. Concentration of Credit Risk: The Company is potentially subject to concentrations of credit risk related to the portion of its unrestricted and restricted cash, cash equivalents, and short‑term investments which is not federally insured, as further discussed in Note C. The Company’s services are provided primarily to customers throughout the United States and, to a lesser extent, Canada, Mexico, and other international locations. On a consolidated basis, the Company had no single customer representing more than 3% of its revenues in 2016, 2015, or 2014 or more than 7% of its accounts receivable balance at December 31, 2016 and 2015. The Company performs ongoing credit evaluations of its customers and generally does not require collateral. Historically, credit losses have been within management’s expectations. Allowances: The Company maintains allowances for doubtful accounts, revenue adjustments, and deferred tax assets. The Company’s allowance for doubtful accounts represents an estimate of potential accounts receivable write‑offs associated with recognized revenue based on historical trends and factors surrounding the credit risk of specific customers. Accounts receivable are written off against the allowance for doubtful accounts and revenue adjustments when accounts are turned over to a collection agency or when the accounts are determined to be uncollectible. The Company’s allowance for revenue adjustments represents an estimate of potential adjustments associated with recognized revenue based upon historical trends and current information regarding trends and business changes. The Company’s valuation allowance for deferred tax assets is determined by evaluating whether it is more likely than not that the benefits of its deferred tax assets will be realized through future reversal of existing taxable temporary differences, taxable income in carryback years, projected future taxable income, or tax‑planning strategies. Property, Plant and Equipment, Including Repairs and Maintenance: Purchases of property, plant and equipment are recorded at cost. For financial reporting purposes, property, plant and equipment is depreciated principally by the straight‑line method, using the following useful lives: structures – primarily 15 to 45 years; revenue equipment – 3 to 12 years; and other equipment – 2 to 20 years. The Company utilizes tractors and trailers in its Asset-Based operations and trailers in its ArcBest segment operations. Tractors and trailers are commonly referred to as “revenue equipment” in the transportation business. The Company periodically reviews and adjusts, as appropriate, the residual values and useful lives of revenue equipment and other equipment. For tax reporting purposes, accelerated depreciation or cost recovery methods are used. Gains and losses on asset sales are reflected in the year of disposal. Exchanges of nonmonetary assets that have commercial substance are measured based on the fair value of the assets exchanged. Tires purchased with revenue equipment are capitalized as a part of the cost of such equipment, with replacement tires being expensed when placed in service. Repair and maintenance costs associated with property, plant and equipment are expensed as incurred if the costs do not extend the useful life of the asset. If such costs do extend the useful life of the asset, the costs are capitalized and depreciated over the appropriate remaining useful life. Computer Software Developed or Obtained for Internal Use, Including Web Site Development Costs: The Company capitalizes the costs of software acquired from third parties and qualifying internal computer software costs incurred during the application development stage. Costs incurred in the preliminary project stage and postimplementation-operation stage, which includes maintenance and training costs, are expensed as incurred. For financial reporting purposes, capitalized software costs are amortized by the straight‑line method generally over 2 to 7 years. The amount of costs capitalized within any period is dependent on the nature of software development activities and projects in each period. Impairment Assessment of Long‑Lived Assets: The Company reviews its long‑lived assets, including property, plant and equipment and capitalized software, which are held and used in its operations, for impairment whenever events or changes in circumstances indicate that the carrying amount of the asset may not be recoverable. If such an event or change in circumstances is present, the Company will estimate the undiscounted future cash flows expected to result from the use of the asset and its eventual disposition. If the sum of the undiscounted future cash flows is less than the carrying amount of the related asset, the Company will recognize an impairment loss. The Company records impairment losses in operating income. Assets to be disposed of are reclassified as assets held for sale at the lower of their carrying amount or fair value less cost to sell. Assets held for sale primarily represent Asset-Based segment nonoperating properties, older revenue equipment, and other equipment. Adjustments to write down assets to fair value less the amount of costs to sell are reported in operating income. Assets held for sale are expected to be disposed of by selling the assets within the next 12 months. Gains and losses on property and equipment are reported in operating income. Assets held for sale of $1.2 million and $2.1 million are reported within other noncurrent assets as of December 31, 2016 and 2015, respectively. At December 31, 2016 and 2015, management was not aware of any events or circumstances indicating the Company’s long‑lived assets would not be recoverable. Goodwill and Intangible Assets: Goodwill represents the excess of the purchase price in a business combination over the fair value of net tangible and intangible assets acquired. Goodwill is not amortized, but rather is evaluated for impairment annually or more frequently if indicators of impairment exist. The Company’s measurement of goodwill impairment involves a comparison of the estimated fair value of a reporting unit to its carrying value. If the estimated fair value of the reporting unit is less than the carrying value, an estimate of the current fair values of all assets and liabilities is made to determine the amount of implied goodwill and, consequently, the amount of any goodwill impairment. Fair value is derived using a combination of valuation methods, including earnings before interest, taxes, depreciation, and amortization (EBITDA) and revenue multiples (market approach) and the present value of discounted cash flows (income approach). Indefinite‑lived intangible assets are also not amortized but rather are evaluated for impairment annually or more frequently if indicators of impairment exist. If the carrying amount of the intangible asset exceeds its fair value, an impairment loss shall be recognized in an amount equal to that excess. Fair values are determined based on a discounted cash flow model, similar to the goodwill analysis. The Company’s annual impairment testing is performed as of October 1. Due to the corporate restructuring, certain changes were made to the reporting units subsequent to the October 1, 2016 annual impairment tests. We evaluated these changes as insignificant to the fair value and carrying value of each individual reporting unit and determined no indicators of impairment exist as of December 31, 2016. The Company amortizes finite‑lived intangible assets over their respective estimated useful lives. Finite‑lived intangible assets are also evaluated for impairment whenever events or changes in circumstances indicate that the carrying value may not be recoverable. In reviewing finite‑lived intangible assets for impairment, the carrying amount of the asset is compared to the estimated undiscounted future cash flows expected from the use of the asset and its eventual disposition. If such cash flows are not sufficient to support the recorded value, an impairment loss to reduce the carrying value of the asset to its estimated fair value shall be recognized in operating income. Income Taxes: The Company accounts for income taxes under the asset and liability method. Under this method, deferred tax assets and liabilities are recognized based on the temporary differences between the book value and the tax basis of certain assets and liabilities and the tax effect of operating loss and tax credit carryforwards. Deferred income taxes relate principally to asset and liability basis differences resulting from the timing of depreciation deductions and to temporary differences in the recognition of certain revenues and expenses. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized as income or expense in the period that includes the enactment date. The Company classifies any interest and penalty amounts related to income tax matters as operating expenses. Management applies considerable judgment in determining the consolidated income tax provision, including valuation allowances on deferred tax assets. The valuation allowance for deferred tax assets is determined by evaluating whether it is more likely than not that the benefits of deferred tax assets will be realized through future reversal of existing taxable temporary differences, taxable income in carryback years, projected future taxable income, or tax‑planning strategies. Uncertain tax positions, which also require significant judgment, are measured to determine the amounts to be recognized in the financial statements. The income tax provision and valuation allowances are complicated by complex and frequently changing rules administered in multiple jurisdictions, including U.S. federal, state, and foreign governments. Book Overdrafts: Issued checks that have not cleared the bank as of December 31 result in book overdraft balances for accounting purposes which are classified within accounts payable in the accompanying consolidated balance sheets. Book overdrafts amounted to $17.7 million and $21.9 million for the year ended December 31, 2016 and 2015, respectively. The change in book overdrafts is reported as a component of financing activities within the statement of cash flows. Claims Liabilities: The Company is self‑insured up to certain limits for workers’ compensation, certain third‑party casualty claims, and cargo loss and damage claims. Amounts in excess of the self‑insured limits are fully insured to levels which management considers appropriate for the Company’s operations. The Company’s claims liabilities have not been discounted. Liabilities for self‑insured workers’ compensation and third‑party casualty claims are based on the case reserve amounts plus an estimate of loss development and incurred but not reported (“IBNR”) claims, which is developed from an independent actuarial analysis. The process of determining reserve requirements utilizes historical trends and involves an evaluation of claim frequency and severity, claims management, and other factors. Case reserves are evaluated as loss experience develops and new information becomes available. Adjustments to previously estimated aggregate reserves are reflected in financial results in the periods in which they are made. Aggregate reserves represent an estimate of the costs of claims incurred, and it is possible that the ultimate liability may differ significantly from such estimates. The Company develops an estimate of self‑insured cargo loss and damage claims liabilities based on historical trends and certain event‑specific information. Long‑Term Debt: As of December 31, 2016 and 2015, long-term debt consisted of borrowings outstanding under the Company’s revolving credit facility and accounts receivable securitization program, minimum principal payments due under notes payable for the financing of revenue equipment, and the present values of net minimum lease payments under capital lease obligations. The Company’s long-term debt and financing arrangements are further described in Note G. Contingent Consideration: The Company records the estimated fair value of contingent consideration at the acquisition date as part of the purchase price consideration for an acquisition. The fair value of the contingent consideration liability was determined by assessing Level 3 inputs with a discounted cash flow approach using various probability-weighted scenarios. As of December 31, 2016, the fair value of the outstanding contingent consideration of $6.8 million related to the acquisition of LDS was recorded in accrued expenses and other long-term liabilities, based on when expected payouts become due. The $8.0 million held in escrow for the contingent consideration at the acquisition date was recorded in other long-term assets. The liability for contingent consideration is remeasured at each quarterly reporting period and any change in fair value as a result of the recurring assessments is recognized in operating income. Interest Rate Swap Derivative Instruments: The Company accounts for its derivative instruments as either assets or liabilities and carries them at fair value. The Company entered into an interest rate swap agreement during 2014 that was designated as a cash flow hedge. The effective portion of the gain or loss on the interest rate swap instrument is reported as unrealized gain or loss as a component of accumulated other comprehensive income or loss, net of tax, in stockholders’ equity and the change in the unrealized gain or loss on the interest rate swap is reported in other comprehensive income or loss, net of tax, in the consolidated statements of comprehensive income. The unrealized gain or loss is reclassified out of accumulated other comprehensive loss into income in the same period or periods during which the hedged transaction affects earnings. The ineffective portion of the gain or loss on the interest rate swap instrument, if any, is recognized in current income. To receive hedge accounting treatment, cash flow hedges must be highly effective in offsetting changes to expected future cash flows on hedged transactions. Leases: The Company leases, under capital and operating lease arrangements, certain facilities, revenue equipment, and certain other equipment used primarily in Asset-Based segment terminal operations. Certain of these leases contain fluctuating or escalating payments. The related rent expense is recorded on a straight‑line basis over the lease term. The cumulative excess of rent expense over rent payments is accounted for as a deferred lease obligation. For financial reporting purposes, assets held under capital leases are depreciated over their estimated useful lives on the same basis as owned assets and leasehold improvements associated with assets utilized under capital or operating leases are amortized by the straight‑line method over the shorter of the remaining lease term or the asset’s useful life. Amortization of assets under capital leases is included in depreciation expense. Obligations under the capital lease arrangements are included in long‑term debt, net of the current portion due, which is classified in current liabilities. Nonunion Defined Benefit Pension, Supplemental Benefit, and Postretirement Health Benefit Plans: The Company recognizes the funded status (the difference between the fair value of plan assets and the benefit obligation) of its nonunion defined benefit pension plan, supplemental benefit plan (“SBP”), and postretirement health benefit plan in the consolidated balance sheet and recognizes changes in the funded status, net of tax, in the year in which they occur as a component of other comprehensive income or loss. Amounts recognized in other comprehensive income or loss are subsequently expensed as components of net periodic benefit cost by amortizing unrecognized net actuarial losses over the average remaining active service period of the plan participants and amortizing unrecognized prior service credits over the remaining years of service until full eligibility of the active participants at the time of the plan amendment which created the prior service credit. A corridor approach is not used for determining the amounts of net actuarial losses to be amortized. The expense and liability related to the Company’s nonunion defined benefit pension plan, SBP, and postretirement health benefit plan are measured based upon a number of assumptions and using the services of a third‑party actuary. Assumptions impacting the Company’s expense for these plans include the discount rate used to discount the plans’ obligations and, for the nonunion defined benefit pension plan, the expected rate of return applied to the fair value of plan assets. The discount rate is determined by matching projected cash distributions with appropriate high‑quality corporate bond yields in a yield curve analysis. The Company establishes the expected long‑term rate of return on plan assets by considering the historical returns for the plan’s current investment mix and the plan investment advisor’s range of expected returns for the plan’s current investment mix. Assumptions are also made regarding expected retirement age, mortality, employee turnover, and future increases in health care costs. The assumptions used directly impact the net periodic benefit cost for a particular year. An actuarial gain or loss results when actual experience varies from the assumptions or when there are changes in actuarial assumptions. Actuarial gains and losses are not included in net periodic benefit cost in the period when they arise but are recognized as a component of other comprehensive income or loss and subsequently amortized as a component of net periodic benefit cost. The Company uses December 31 as the measurement date for its nonunion defined benefit pension plan, SBP, and postretirement health benefit plan. Plan obligations are also remeasured upon curtailment and upon settlement. The Company records quarterly pension settlement expense related to the nonunion defined benefit pension plan when qualifying distributions determined to be settlements are expected to exceed the estimated total annual interest cost of the plan. Benefit distributions under the SBP individually exceed the annual interest cost of the plan, and the Company records the related settlement expense when the amount of the benefit to be distributed is fixed, which is generally upon an employee’s termination of employment. Pension settlement expense for the nonunion defined benefit pension and SBP plans is presented in Note I. Revenue Recognition: Asset-Based segment revenue is recognized based on relative transit time in each reporting period with expenses recognized as incurred. A bill-by-bill analysis is used to establish estimates of revenue in transit for recognition in the appropriate reporting period. ArcBest segment revenue is recognized based on the delivery of the shipment to the customer-designated location. Service fee revenue for the FleetNet segment is recognized upon occurrence of the service event. Repair revenue and expenses for the FleetNet segment are recognized at the completion of the service by third-party vendors. Revenue, purchased transportation expense, and third‑party service expenses are reported on a gross basis for certain shipments and services where the Company utilizes a third‑party carrier for pickup, linehaul, delivery of freight, or performance of services but remains the primary obligor and assumes collection and credit risks. Comprehensive Income or Loss: Comprehensive income or loss consists of net income and other comprehensive income or loss, net of tax. Other comprehensive income or loss refers to revenues, expenses, gains, and losses that are not included in net income, but rather are recorded directly to stockholders’ equity. The Company reports the components of other comprehensive income or loss, net of tax, by their nature and discloses the tax effect allocated to each component in the consolidated statements of comprehensive income. The accumulated balance of other comprehensive income or loss is displayed separately in the consolidated statements of stockholders’ equity and the components of the balance are reported in Note J. The changes in accumulated other comprehensive income or loss, net of tax, and the significant reclassifications out of accumulated other comprehensive income or loss are disclosed, by component, in Note J. Earnings Per Share: The Company uses the two‑class method for calculating earnings per share due to certain equity awards being deemed participating securities. The two-class method is an earnings allocation method under which earnings per share is calculated for each class of common stock and participating security considering both dividends declared and participation rights in undistributed earnings as if all such earnings had been distributed during the period. The calculation uses the net income based on the two-class method and the weighted‑average number of common shares (basic earnings per share) or common equivalent shares outstanding (diluted earnings per share) during the applicable period. The dilutive effect of common stock equivalents is excluded from basic earnings per common share and included in the calculation of diluted earnings per common share. Share‑Based Compensation: The fair value of restricted stock awards is determined based upon the closing market price of the Company’s common stock on the date of grant. The restricted stock units generally vest at the end of a five‑year period following the date of grant, except for certain awards granted to non‑employee directors that typically vest at the end of a one-year period for awards granted on or after January 1, 2016 and at the end of a three‑year period for previous grants, subject to accelerated vesting due to death, disability, retirement, or change‑in‑control provisions. When restricted stock units become vested, the Company issues new shares which are subsequently distributed. Dividends or dividend equivalents are paid on certain restricted stock units during the vesting period. The Company recognizes the income tax benefits of dividends on share‑based payment awards as an increase in paid‑in capital. Share‑based awards are amortized to compensation expense on a straight‑line basis over the vesting period of awards or over the period to which the recipient first becomes eligible for retirement, whichever is shorter, with vesting accelerated upon death or disability. Compensation expense reflects an estimate of shares expected to be forfeited over the service period. Estimated forfeitures, which are based on historical experience, are adjusted to the extent that actual forfeitures differ, or are expected to differ, from these estimates. Fair Value Measurements: The Company discloses the fair value measurements of its financial assets and liabilities. Fair value measurements for investments held in trust for the Company’s nonunion defined benefit pension plan are also disclosed. Fair value measurements are disclosed in accordance with the following hierarchy of valuation techniques based on whether the inputs of market data and market assumptions used to measure fair value are observable or unobservable:
| · |  | Level 1 – Quoted prices for identical assets and liabilities in active markets.
| · |  | Level 2 – Quoted prices for similar assets and liabilities in active markets, quoted prices for identical or similar assets and liabilities in markets that are not active, or other inputs that are observable or can be corroborated by observable market data.
| · |  | Level 3 – Unobservable inputs (Company’s market assumptions) that are significant to the valuation model. The Level 3 assessments utilize a Monte Carlo simulation with inputs including scenarios of estimated revenues and gross margins to be achieved for applicable performance periods, probability weightings assigned to performance scenarios, and discount rates.
Environmental Matters: The Company expenses environmental costs related to existing conditions resulting from past or current operations and from which no current or future benefit is discernible. Expenditures which extend the life of the related property or mitigate or prevent future environmental contamination are capitalized. Amounts accrued reflect management’s best estimate of the future undiscounted exposure related to identified properties based on current environmental regulations, management’s experience with similar environmental matters, and testing performed at certain sites. The estimated liability is not reduced for possible recoveries from insurance carriers or other third parties. Exit or Disposal Activities: The Company recognizes liabilities for costs associated with exit or disposal activities when the liability is incurred. Adopted Accounting Pronouncements: In the first quarter of 2016, the Company adopted guidance issued by the Financial Accounting Standards Board (the “FASB”) which amended Accounting Standards Codification (“ASC”) Topic 835, Interest – Imputation of Interest, and addresses the presentation of debt issuance costs in the balance sheet. The Company’s debt issuance costs related to its revolving credit agreements continue to be presented as an asset, as permitted, and amortized over the term of the agreements within interest expense. The new guidance did not result in retrospective adjustments to the consolidated financial statements or disclosures. During first quarter 2016, the Company adopted amended ASC Topic 805, Business Combinations, issued by the FASB. The amendment eliminated the requirement that an acquirer in a business combination account for measurement-period adjustments retrospectively and instead recognize measurement-period adjustments during the period in which it determines the amount of the adjustments, including the effect on earnings of any amounts it would have recorded in previous periods if the accounting had been completed at the acquisition date. The amendment was prospectively adopted and did not result in significant adjustments to financial statements or disclosure presentation. In the fourth quarter of 2016, the Company adopted accounting pronouncement to amend ASC Topic 205 with the addition of Presentation of Financial Statements – Going Concern (Subtopic 205-40), issued by the FASB. The amendment requires an entity’s management to assess conditions and events to determine the entity’s ability to continue as a going concern for each annual and interim reporting period for which financial statements are issued. Accounting Pronouncements Not Yet Adopted: ASC Topic 740 was amended with the addition of Balance Sheet Classification of Deferred Taxes. The amendment is effective for the Company beginning January 1, 2017. The update will result in all deferred tax assets and liabilities being classified as noncurrent in the consolidated balance sheets. An amendment to ASC Topic 718, Compensation – Stock Compensation, was issued to simplify the accounting for share-based compensation, which will require the income tax effects of awards to be recognized in the statement of operations when awards vest or are settled and will allow employers to make a policy election to account for forfeitures as they occur. The Company is required to adopt the amendments in the first quarter of 2017. Subsequent to adoption, the Company may experience volatility in its income tax provision as a result of recording all excess tax benefits and tax deficiencies in the income statement upon settlement of awards, which is primarily during the second quarter of each year. All other adopted provisions of the amendment are not expected to have a significant impact on our consolidated financial statements, including the Company electing to record forfeitures as they occur. ASC Topic 606, which amends the guidance in former ASC Topic 605, Revenue Recognition, provides a single comprehensive revenue recognition model for all contracts with customers and contains principles to apply to determine the measurement of revenue and timing of when it is recognized. The standard is effective for the Company on January 1, 2018. The Company plans to adopt this standard on the modified retrospective basis and does not expect a significant impact on the consolidated financial statements. An amendment to ASC Topic 230, Statement of Cash Flows, which provides classification guidance for restricted cash and for certain cash payments and receipts presented in the statement of cash flows, is effective for the Company beginning January 1, 2018 and is not expected to have a significant on the Company’s consolidated financial statements. ASC Topic 842, Leases, which is effective for the Company beginning January 1, 2019, will require leases with a term greater than twelve months to be reflected as liabilities with associated right-of-use assets in the Company’s consolidated balance sheet. The Company is evaluating the impact of the new standard on the consolidated financial statements. An amendment to ASC Topic 326, Measurement of Credit Losses on Financial Instruments, which changes the impairment model for most financial assets and certain other instruments, is effective for the Company beginning January 1, 2020. The Company is currently assessing the impact this update will have on the consolidated financial statements and disclosures. Management believes that there is no other new accounting guidance issued but not yet effective that is relevant to the Company’s current financial statements. However, there are new proposals under development by the standard setting bodies which, if and when enacted, may have a significant impact on our financial statements, including changes in disclosure requirements for income taxes and defined benefit plans.

X
- References No definition available. + Details
Name: | us-gaap_AccountingPoliciesAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The entire disclosure for all significant accounting policies of the reporting entity. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section 50 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=68058157&loc=d3e18861-107790 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=68058157&loc=d3e18780-107790 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=68058157&loc=d3e18726-107790 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=68058157&loc=d3e18743-107790 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section 50 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=68058157&loc=d3e18854-107790 + Details
Name: | us-gaap_SignificantAccountingPoliciesTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration