| **Incentive Plans and Stock-Based Compensation - Stock Options Compensation Expense (Details) - Employee and Non-Employee Stock Options [Member] - USD ($) $ in Thousands** | 3 Months Ended | 9 Months Ended |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------|----------------|
||
| **Share-based Compensation Arrangement by Share-based Payment Award [Line Items]**                                                                                          |           |           |   |   |
| Pre-tax compensation expense                                                                                                                                                | $ 522          | $ 896          | $ 2,346 | $ 4,460 |
| Deferred tax benefits                                                                                                                                                       | (190)          | (326)          | (853) | (1,622) |
| Excess tax benefits associated with tax deductions over the amount of compensation expense recognized in the consolidated condensed financial statements                    | 981            | 139            | 1,804 | 923 |
| Fair value of stock options on date of grant                                                                                                                                | 0              | 0              | 2,144 | 3,196 |
| Total intrinsic value of stock options exercised                                                                                                                            | 5,991          | 535            | 12,230 | 3,699 |
| Cash received upon exercise of stock options                                                                                                                                | 13,830         | 710            | 29,292 | 5,306 |
| Addition to capital in excess of par value due to exercise of stock options                                                                                                 | $ 14,491       | $ 830          | $ 30,392 | $ 6,079 |

| X                                                                                                                                                                                                                                                                                                                                                                                                                                 |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.
+ References
No definition available.
+ Details**Name:**clc_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGrantDateFairValue**Namespace Prefix:**clc_**Data Type:**xbrli:monetaryItemType**Balance Type:**debit**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of increase (decrease) in additional paid in capital (APIC) resulting from a tax benefit (deficiency) associated with an share-based compensation plan other than an employee stock ownership plan (ESOP).
+ References
No definition available.
+ Details**Name:**us-gaap_AdjustmentToAdditionalPaidInCapitalIncomeTaxEffectFromShareBasedCompensationNet**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Changes in additional paid in capital related to exercise of share-based payments awards (such as stock options) and the amount of recognized equity-based compensation during the period (such as nonvested shares).
+ References
No definition available.
+ Details**Name:**us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationAndExerciseOfStockOptions**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SAB Topic 14.F) -URI http://asc.fasb.org/extlink&oid=27013229&loc=d3e301413-122809Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5047-113901Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (h)(1)(i) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901
+ Details**Name:**us-gaap_AllocatedShareBasedCompensationExpense**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**debit**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Aggregate proceeds received by the entity during the annual period from exercises of stock or unit options and conversion of similar instruments granted under equity-based payment arrangements.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (j) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901
+ Details**Name:**us-gaap_EmployeeServiceShareBasedCompensationCashReceivedFromExerciseOfStockOptions**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**debit**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The total recognized tax benefit related to compensation cost for equity-based payment arrangements recognized in income during the period.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (h)(1)(i) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901
+ Details**Name:**us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.
+ References
No definition available.
+ Details**Name:**us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems**Namespace Prefix:**us-gaap_**Data Type:**xbrli:stringItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (d)(2) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901
+ Details**Name:**us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**debit**Period Type:**duration |
| X                                                                                                                                                          |
|------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_AwardTypeAxis=clc_EmployeeandNonEmployeeStockOptionsMember**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |