Name:	knl_DefinedContributionBenefitPlansLineItems
Namespace Prefix:	knl_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Represents the number of shares of common stock into which participants may invest the compensation they elect to defer.

+ References

No definition available.

+ Details

Name:	knl_DefinedContributionPlanCommonStockSharesIntoWhichParticipantsMayInvestCompensation
Namespace Prefix:	knl_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the period for vesting of the company contributions for the defined contribution plans.

+ References

No definition available.

+ Details

Name:	knl_DefinedContributionPlanEmployerContributionsVestingPeriod
Namespace Prefix:	knl_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the maximum percentage of non union and union employees' annual compensation eligible for employer's matching contribution.

+ References

No definition available.

+ Details

Name:	knl_DefinedContributionPlanMaximumDiscretionaryEmployerMatchingContributionAsPercentageOfParticipantContributionForFirstSixPercentOfNonUnionAndUnionEmployeesAnnualCompensation
Namespace Prefix:	knl_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the maximum participant contributions in the Knoll common stock fund, expressed as a percentage of their total account balance in the plan.

+ References

No definition available.

+ Details

Name:	knl_DefinedContributionPlanMaximumParticipantContributionsAsPercentageOfAccountBalanceInPlan
Namespace Prefix:	knl_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the maximum discretionary employer matching contribution as a percentage of participant contributions for the first 6.0 percent of non union and union employees' annual compensation.

+ References

No definition available.

+ Details

Name:	knl_DefinedContributionPlanMaximumPercentageOfNonUnionAndUnionEmployeesAnnualCompensationEligibleForEmployerContributionMatch
Namespace Prefix:	knl_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount of the cost recognized during the period for defined contribution plans.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 70

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6414718&loc=d3e28014-114942

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 132R

-Paragraph 11

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

Name:	us-gaap_DefinedContributionPlanCostRecognized
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

PENSION AND OTHER POSTRETIREMENT BENEFITS (Details 4) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended				1 Months Ended
	Dec. 31, 2012	Dec. 31, 2012 Contribution plan for Canadian, Belgium and United Kingdom employees	Dec. 31, 2011 Contribution plan for Canadian, Belgium and United Kingdom employees	Dec. 31, 2010 Contribution plan for Canadian, Belgium and United Kingdom employees	Dec. 31, 2010 Contribution plan for US employees	Jan. 31, 2010 Contribution plan for US employees
Defined contribution plan
Total expense	$ 3.0	$ 1.3	$ 1.2	$ 1.1
Fixed matching contribution as a percentage of participant contributions for the first 6.0% of both nonunion and union employees' annual compensation						50.00%
Maximum percentage of nonunion and union employees' compensation eligible for employer contribution match, towards defined contribution plan						6.00%
Company contributions vesting period						5 years
Number of shares of common stock into which participants may invest the compensation they elect to defer					1,000,000
Maximum participant contributions in the Knoll common stock fund as a percentage of their total account balance in the plan					10.00%