Summary of Significant Accounting Policies (Policies)	12 Months Ended
Dec. 31, 2013
Summary of Significant Accounting Policies [Abstract]
Nature of Operations	Nature of Operations – Our primary business is designing, manufacturing and marketing solutions that help create a cleaner, safer, healthier world. Our products include equipment for maintaining surfaces in industrial, commercial and outdoor environments; chemical-free and other sustainable cleaning technologies; and coatings for protecting, repairing and upgrading floors and other surfaces. We sell our products through our direct sales and service organization and a network of authorized distributors worldwide. Geographically, our customers are located in North America, Latin America, Europe, the Middle East, Africa and Asia Pacific.
Consolidation	Consolidation – The Consolidated Financial Statements include the accounts of Tennant Company and its subsidiaries. All intercompany transactions and balances have been eliminated. In these Notes to the Consolidated Financial Statements, Tennant Company is referred to as “Tennant,” “we,” “us,” or “our.”
Translations of Non-U.S. Currency	Translation of Non-U.S. Currency – Foreign currency-denominated assets and liabilities have been translated to U.S. dollars at year-end exchange rates, while income and expense items are translated at average exchange rates prevailing during the year. Gains or losses resulting from translation are included as a separate component of Accumulated Other Comprehensive Loss. The balance of cumulative foreign currency translation adjustments recorded within Accumulated Other Comprehensive Loss as of December 31, 2013, 2012 and 2011 was a net loss of $21,991, $19,734 and $20,283, respectively. The majority of translation adjustments are not adjusted for income taxes as substantially all translation adjustments relate to permanent investments in non-U.S. subsidiaries. Net Foreign Currency Transaction (Losses) Gains are included in Other Income (Expense).
Use of Estimates	Use of Estimates – In preparing the consolidated financial statements in conformity with U.S. generally accepted accounting principles ("U.S. GAAP"), management must make decisions that impact the reported amounts of assets, liabilities, revenues, expenses and the related disclosures, including disclosures of contingent assets and liabilities. Such decisions include the selection of the appropriate accounting principles to be applied and the assumptions on which to base accounting estimates. Estimates are used in determining, among other items, sales promotions and incentives accruals, inventory valuation, warranty reserves, allowance for doubtful accounts, pension and postretirement accruals, useful lives for intangible assets, and future cash flows associated with impairment testing for goodwill and other long-lived assets. These estimates and assumptions are based on management’s best estimates and judgments. Management evaluates its estimates and assumptions on an ongoing basis using historical experience and other factors that management believes to be reasonable under the circumstances. We adjust such estimates and assumptions when facts and circumstances dictate. A number of these factors include, among others, economic conditions, credit markets, foreign currency, commodity cost volatility and consumer spending and confidence, all of which have combined to increase the uncertainty inherent in such estimates and assumptions. As future events and their effects cannot be determined with precision, actual amounts could differ significantly from those estimated at the time the consolidated financial statements are prepared. Changes in those estimates resulting from continuing changes in the economic environment will be reflected in the financial statements in future periods.
Cash and Cash Equivalents	Cash and Cash Equivalents – We consider all highly liquid investments with maturities of three months or less from the date of purchase to be cash equivalents.
Restricted Cash	Restricted Cash – We have a total of $393 as of December 31, 2013 that serves as collateral backing certain bank guarantees and is therefore restricted. This money is invested in time deposits.
Receivables	Receivables – Credit is granted to our customers in the normal course of business. Receivables are recorded at original carrying value less reserves for estimated uncollectible accounts and sales returns. To assess the collectability of these receivables, we perform ongoing credit evaluations of our customers’ financial condition. Through these evaluations, we may become aware of a situation where a customer may not be able to meet its financial obligations due to deterioration of its financial viability, credit ratings or bankruptcy. The reserve requirements are based on the best facts available to us and are reevaluated and adjusted as additional information becomes available. Our reserves are also based on amounts determined by using percentages applied to trade receivables. These percentages are determined by a variety of factors including, but not limited to, current economic trends, historical payment and bad debt write-off experience. An account is considered past-due or delinquent when it has not been paid within the contractual terms. Uncollectible accounts are written off against the reserves when it is deemed that a customer account is uncollectible.
Inventories	Inventories – Inventories are valued at the lower of cost or market. Cost is determined on a first-in, first-out (“FIFO”) basis except for Inventories in North America and Japan which are determined on a last-in, first-out (“LIFO”) basis.
Property, Plant and Equipment	Property, Plant and Equipment – Property, plant and equipment is carried at cost. Additions and improvements that extend the lives of the assets are capitalized while expenditures for repairs and maintenance are expensed as incurred. We generally depreciate buildings and improvements by the straight-line method over a life of 30 years . Other property, plant and equipment are generally depreciated using the straight-line method based on lives of 3 years to 15 years.
Goodwill	Goodwill – Goodwill represents the excess of cost over the fair value of net assets of businesses acquired. We analyze Goodwill on an annual basis as of year end and when an event occurs or circumstances change that may reduce the fair value of one of our reporting units below its carrying amount. A goodwill impairment occurs if the carrying amount of a reporting unit’s goodwill exceeds its fair value. In assessing the recoverability of Goodwill, we use an analysis of qualitative factors to determine whether it is more likely than not that the fair value of a reporting unit is less than its carrying amount as a basis for determining whether it is necessary to perform the two-step goodwill impairment test.
Intangible Assets	Intangible Assets – Intangible Assets consist of definite lived customer lists, service contracts, an acquired trade name and technology. Intangible Assets with a definite life are amortized on a straight-line basis.
Impairment of Long-lived Assets	Impairment of Long-lived Assets – We periodically review our intangible and long-lived assets for impairment and assess whether events or circumstances indicate that the carrying amount of the assets may not be recoverable. We generally deem an asset group to be impaired if an estimate of undiscounted future operating cash flows is less than its carrying amount. If impaired, an impairment loss is recognized based on the excess of the carrying amount of the individual asset group over its fair value.
Purchases of Common Stock	Purchases of Common Stock – We repurchase our Common Stock under a 2011 and a 2012 repurchase program authorized by our Board of Directors. These programs allow us to repurchase up to 2,000,000 shares of our Common Stock. Upon repurchase, the par value is charged to Common Stock and the remaining purchase price is charged to Additional Paid-in Capital. If the amount of the remaining purchase price causes the Additional Paid-in Capital account to be in a debit position, this amount is then reclassified to Retained Earnings. Common Stock repurchased is included in shares authorized but is not included in shares outstanding.
Warranty	Warranty – We record a liability for estimated warranty claims at the time of sale. The amount of the liability is based on the trend in the historical ratio of claims to sales, the historical length of time between the sale and resulting warranty claim, new product introductions and other factors. In the event we determine that our current or future product repair and replacement costs exceed our estimates, an adjustment to these reserves would be charged to earnings in the period such determination is made. Warranty terms on machines range from one to four years.
Environmental	Environmental – We record a liability for environmental clean-up on an undiscounted basis when a loss is probable and can be reasonably estimated.
Pension and Profit Sharing Plans	Pension and Profit Sharing Plans – We have pension and/or profit sharing plans covering substantially all of our employees. Pension plan costs are accrued based on actuarial estimates with the required pension cost funded annually, as needed. No new participants have entered the pension plan since 2000.
Postretirement Benefits	Postretirement Benefits – We accrue and recognize the cost of retiree health benefits over the employees’ period of service based on actuarial estimates. Benefits are only available for U.S. employees hired before January 1, 1999.
Derivative Financial Instruments	Derivative Financial Instruments – We use derivative instruments to manage exposures to foreign currency only in an attempt to limit underlying exposures from currency fluctuations and not for trading purposes. We periodically enter into various contracts, principally forward exchange contracts, to protect the value of certain of our foreign currency-denominated assets and liabilities (principally the Euro, Australian and Canadian dollars, British pound, Japanese yen, Chinese yuan and Brazilian real). We have elected not to apply hedge accounting treatment to these contracts as our contracts are for a short duration. These contracts are marked-to-market with the related asset or liability recorded in Other Current Assets or Other Current Liabilities, as applicable. The gains and losses on these contracts generally approximate changes in the value of the related assets and liabilities. Gains or losses on forward foreign exchange contracts to economically hedge foreign currency-denominated net assets and liabilities are recognized in Other Income (Expense) under Net Foreign Currency Transaction (Losses) Gains within the Consolidated Statements of Earnings.
Revenue Recognition	Revenue Recognition – We recognize revenue when persuasive evidence of an arrangement exists, title and risk of ownership have passed to the customer, the sales price is fixed or determinable and collectibility is reasonably assured. Generally, these criteria are met at the time the product is shipped. Provisions for estimated returns, rebates and discounts are provided for at the time the related revenue is recognized. Freight revenue billed to customers is included in Net Sales and the related shipping expense is included in Cost of Sales. Service revenue is recognized in the period the service is performed or ratably over the period of the related service contract. Customers may obtain financing through third-party leasing companies to assist in their acquisition of our equipment products. Certain lease transactions classified as operating leases contain retained ownership provisions or guarantees, which results in recognition of revenue over the lease term. As a result, we defer the sale of these transactions and record the sales proceeds as collateralized borrowings or deferred revenue. The underlying equipment relating to operating leases is depreciated on a straight-line basis, not to exceed the equipment’s estimated useful life. Revenues from contracts with multiple element arrangements are recognized as each element is earned. We offer service contracts in conjunction with equipment sales in addition to selling equipment and service contracts separately. Sales proceeds related to service contracts are deferred if the proceeds are received in advance of the service and recognized ratably over the contract period.
Share-based Compensation	Share-based Compensation – We account for employee share-based compensation using the fair value based method. Our share-based compensation plans are more fully described in Note 15 of the Consolidated Financial Statements.
Research and Development	Research and Development – Research and development costs are expensed as incurred.
Advertising Costs	Advertising Costs – We advertise products, technologies and solutions to customers and prospective customers through a variety of marketing campaign and promotional efforts. These efforts include tradeshows, online advertising, e-mail marketing, mailings, sponsorships and telemarketing. Advertising costs are expensed as incurred. In 2013, 2012 and 2011 such activities amounted to $6,412, $6,466 and $6,728, respectively.
Income Taxes	Income Taxes – Deferred tax assets and liabilities are recognized for the expected future tax consequences of temporary differences between the book and tax bases of existing assets and liabilities. A valuation allowance is provided when, in management’s judgment, it is more likely than not that some portion or all of the deferred tax asset will not be realized. We have established contingent tax liabilities using management’s best judgment. We follow guidance provided by Accounting Standards Codification ("ASC") 740, Income Taxes, regarding uncertainty in income taxes, to record these contingent tax liabilities (refer to Note 14 of the Consolidated Financial Statements for additional information). We adjust these liabilities as facts and circumstances change. Interest Expense is recognized in the first period the interest would begin accruing. Penalties are recognized in the period we claim or expect to claim the position in our tax return. Interest and penalties expenses are classified as an income tax expense.
Sales Tax	Sales Tax – Sales taxes collected from customers and remitted to governmental authorities are presented on a net basis.
Earnings per Share	Earnings per Share – Basic earnings per share is computed by dividing Net Earnings by the Weighted Average Shares Outstanding during the period. Diluted earnings per share assume conversion of potentially dilutive stock options and restricted share awards. Performance-based shares are included in the calculation of diluted earnings per share in the quarter in which the performance targets have been achieved.

Summary of Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2013

Summary of Significant Accounting Policies [Abstract]

Nature of Operations – Our primary business is designing, manufacturing and marketing solutions that help create a cleaner, safer, healthier world. Our products include equipment for maintaining surfaces in industrial, commercial and outdoor environments; chemical-free and other sustainable cleaning technologies; and coatings for protecting, repairing and upgrading floors and other surfaces. We sell our products through our direct sales and service organization and a network of authorized distributors worldwide. Geographically, our customers are located in North America, Latin America, Europe, the Middle East, Africa and Asia Pacific.

Consolidation

Consolidation – The Consolidated Financial Statements include the accounts of Tennant Company and its subsidiaries. All intercompany transactions and balances have been eliminated. In these Notes to the Consolidated Financial Statements, Tennant Company is referred to as “Tennant,” “we,” “us,” or “our.”

Translations of Non-U.S. Currency

Translation of Non-U.S. Currency – Foreign currency-denominated assets and liabilities have been translated to U.S. dollars at year-end exchange rates, while income and expense items are translated at average exchange rates prevailing during the year. Gains or losses resulting from translation are included as a separate component of Accumulated Other Comprehensive Loss. The balance of cumulative foreign currency translation adjustments recorded within Accumulated Other Comprehensive Loss as of December 31, 2013, 2012 and 2011 was a net loss of $21,991, $19,734 and $20,283, respectively. The majority of translation adjustments are not adjusted for income taxes as substantially all translation adjustments relate to permanent investments in non-U.S. subsidiaries. Net Foreign Currency Transaction (Losses) Gains are included in Other Income (Expense).

Use of Estimates

Use of Estimates – In preparing the consolidated financial statements in conformity with U.S. generally accepted accounting principles ("U.S. GAAP"), management must make decisions that impact the reported amounts of assets, liabilities, revenues, expenses and the related disclosures, including disclosures of contingent assets and liabilities. Such decisions include the selection of the appropriate accounting principles to be applied and the assumptions on which to base accounting estimates. Estimates are used in determining, among other items, sales promotions and incentives accruals, inventory valuation, warranty reserves, allowance for doubtful accounts, pension and postretirement accruals, useful lives for intangible assets, and future cash flows associated with impairment testing for goodwill and other long-lived assets. These estimates and assumptions are based on management’s best estimates and judgments. Management evaluates its estimates and assumptions on an ongoing basis using historical experience and other factors that management believes to be reasonable under the circumstances. We adjust such estimates and assumptions when facts and circumstances dictate. A number of these factors include, among others, economic conditions, credit markets, foreign currency, commodity cost volatility and consumer spending and confidence, all of which have combined to increase the uncertainty inherent in such estimates and assumptions. As future events and their effects cannot be determined with precision, actual amounts could differ significantly from those estimated at the time the consolidated financial statements are prepared. Changes in those estimates resulting from continuing changes in the economic environment will be reflected in the financial statements in future periods.

Cash and Cash Equivalents

Cash and Cash Equivalents – We consider all highly liquid investments with maturities of three months or less from the date of purchase to be cash equivalents.

Restricted Cash

Restricted Cash – We have a total of $393 as of December 31, 2013 that serves as collateral backing certain bank guarantees and is therefore restricted. This money is invested in time deposits.

Receivables

Receivables – Credit is granted to our customers in the normal course of business. Receivables are recorded at original carrying value less reserves for estimated uncollectible accounts and sales returns. To assess the collectability of these receivables, we perform ongoing credit evaluations of our customers’ financial condition. Through these evaluations, we may become aware of a situation where a customer may not be able to meet its financial obligations due to deterioration of its financial viability, credit ratings or bankruptcy. The reserve requirements are based on the best facts available to us and are reevaluated and adjusted as additional information becomes available. Our reserves are also based on amounts determined by using percentages applied to trade receivables. These percentages are determined by a variety of factors including, but not limited to, current economic trends, historical payment and bad debt write-off experience. An account is considered past-due or delinquent when it has not been paid within the contractual terms. Uncollectible accounts are written off against the reserves when it is deemed that a customer account is uncollectible.

Inventories

Inventories – Inventories are valued at the lower of cost or market. Cost is determined on a first-in, first-out (“FIFO”) basis except for Inventories in North America and Japan which are determined on a last-in, first-out (“LIFO”) basis.

Property, Plant and Equipment

Property, Plant and Equipment – Property, plant and equipment is carried at cost. Additions and improvements that extend the lives of the assets are capitalized while expenditures for repairs and maintenance are expensed as incurred. We generally depreciate buildings and improvements by the straight-line method over a life of 30 years . Other property, plant and equipment are generally depreciated using the straight-line method based on lives of 3 years to 15 years.

Goodwill

Goodwill – Goodwill represents the excess of cost over the fair value of net assets of businesses acquired. We analyze Goodwill on an annual basis as of year end and when an event occurs or circumstances change that may reduce the fair value of one of our reporting units below its carrying amount. A goodwill impairment occurs if the carrying amount of a reporting unit’s goodwill exceeds its fair value. In assessing the recoverability of Goodwill, we use an analysis of qualitative factors to determine whether it is more likely than not that the fair value of a reporting unit is less than its carrying amount as a basis for determining whether it is necessary to perform the two-step goodwill impairment test.

Intangible Assets

Intangible Assets – Intangible Assets consist of definite lived customer lists, service contracts, an acquired trade name and technology. Intangible Assets with a definite life are amortized on a straight-line basis.

Impairment of Long-lived Assets

Impairment of Long-lived Assets – We periodically review our intangible and long-lived assets for impairment and assess whether events or circumstances indicate that the carrying amount of the assets may not be recoverable. We generally deem an asset group to be impaired if an estimate of undiscounted future operating cash flows is less than its carrying amount. If impaired, an impairment loss is recognized based on the excess of the carrying amount of the individual asset group over its fair value.

Purchases of Common Stock

Purchases of Common Stock – We repurchase our Common Stock under a 2011 and a 2012 repurchase program authorized by our Board of Directors. These programs allow us to repurchase up to 2,000,000 shares of our Common Stock. Upon repurchase, the par value is charged to Common Stock and the remaining purchase price is charged to Additional Paid-in Capital. If the amount of the remaining purchase price causes the Additional Paid-in Capital account to be in a debit position, this amount is then reclassified to Retained Earnings. Common Stock repurchased is included in shares authorized but is not included in shares outstanding.

Warranty

Warranty – We record a liability for estimated warranty claims at the time of sale. The amount of the liability is based on the trend in the historical ratio of claims to sales, the historical length of time between the sale and resulting warranty claim, new product introductions and other factors. In the event we determine that our current or future product repair and replacement costs exceed our estimates, an adjustment to these reserves would be charged to earnings in the period such determination is made. Warranty terms on machines range from one to four years.

Environmental

Environmental – We record a liability for environmental clean-up on an undiscounted basis when a loss is probable and can be reasonably estimated.

Pension and Profit Sharing Plans

Pension and Profit Sharing Plans – We have pension and/or profit sharing plans covering substantially all of our employees. Pension plan costs are accrued based on actuarial estimates with the required pension cost funded annually, as needed. No new participants have entered the pension plan since 2000.

Postretirement Benefits

Postretirement Benefits – We accrue and recognize the cost of retiree health benefits over the employees’ period of service based on actuarial estimates. Benefits are only available for U.S. employees hired before January 1, 1999.

Derivative Financial Instruments

Derivative Financial Instruments – We use derivative instruments to manage exposures to foreign currency only in an attempt to limit underlying exposures from currency fluctuations and not for trading purposes. We periodically enter into various contracts, principally forward exchange contracts, to protect the value of certain of our foreign currency-denominated assets and liabilities (principally the Euro, Australian and Canadian dollars, British pound, Japanese yen, Chinese yuan and Brazilian real). We have elected not to apply hedge accounting treatment to these contracts as our contracts are for a short duration. These contracts are marked-to-market with the related asset or liability recorded in Other Current Assets or Other Current Liabilities, as applicable. The gains and losses on these contracts generally approximate changes in the value of the related assets and liabilities. Gains or losses on forward foreign exchange contracts to economically hedge foreign currency-denominated net assets and liabilities are recognized in Other Income (Expense) under Net Foreign Currency Transaction (Losses) Gains within the Consolidated Statements of Earnings.

Revenue Recognition

Revenue Recognition – We recognize revenue when persuasive evidence of an arrangement exists, title and risk of ownership have passed to the customer, the sales price is fixed or determinable and collectibility is reasonably assured. Generally, these criteria are met at the time the product is shipped. Provisions for estimated returns, rebates and discounts are provided for at the time the related revenue is recognized. Freight revenue billed to customers is included in Net Sales and the related shipping expense is included in Cost of Sales. Service revenue is recognized in the period the service is performed or ratably over the period of the related service contract.

Customers may obtain financing through third-party leasing companies to assist in their acquisition of our equipment products. Certain lease transactions classified as operating leases contain retained ownership provisions or guarantees, which results in recognition of revenue over the lease term. As a result, we defer the sale of these transactions and record the sales proceeds as collateralized borrowings or deferred revenue. The underlying equipment relating to operating leases is depreciated on a straight-line basis, not to exceed the equipment’s estimated useful life.

Revenues from contracts with multiple element arrangements are recognized as each element is earned. We offer service contracts in conjunction with equipment sales in addition to selling equipment and service contracts separately. Sales proceeds related to service contracts are deferred if the proceeds are received in advance of the service and recognized ratably over the contract period.

Share-based Compensation

Share-based Compensation – We account for employee share-based compensation using the fair value based method. Our share-based compensation plans are more fully described in Note 15 of the Consolidated Financial Statements.

Research and Development

Research and Development – Research and development costs are expensed as incurred.

Advertising Costs

Advertising Costs – We advertise products, technologies and solutions to customers and prospective customers through a variety of marketing campaign and promotional efforts. These efforts include tradeshows, online advertising, e-mail marketing, mailings, sponsorships and telemarketing. Advertising costs are expensed as incurred. In 2013, 2012 and 2011 such activities amounted to $6,412, $6,466 and $6,728, respectively.

Income Taxes

Income Taxes – Deferred tax assets and liabilities are recognized for the expected future tax consequences of temporary differences between the book and tax bases of existing assets and liabilities. A valuation allowance is provided when, in management’s judgment, it is more likely than not that some portion or all of the deferred tax asset will not be realized. We have established contingent tax liabilities using management’s best judgment. We follow guidance provided by Accounting Standards Codification ("ASC") 740, Income Taxes, regarding uncertainty in income taxes, to record these contingent tax liabilities (refer to Note 14 of the Consolidated Financial Statements for additional information). We adjust these liabilities as facts and circumstances change. Interest Expense is recognized in the first period the interest would begin accruing. Penalties are recognized in the period we claim or expect to claim the position in our tax return. Interest and penalties expenses are classified as an income tax expense.

Sales Tax

Sales Tax – Sales taxes collected from customers and remitted to governmental authorities are presented on a net basis.

Earnings per Share

Earnings per Share – Basic earnings per share is computed by dividing Net Earnings by the Weighted Average Shares Outstanding during the period. Diluted earnings per share assume conversion of potentially dilutive stock options and restricted share awards. Performance-based shares are included in the calculation of diluted earnings per share in the quarter in which the performance targets have been achieved.