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Shareholders' Equity - Narrative (Details) - USD ($) | 3 Months Ended | 9 Months Ended
--- | --- | ---
Oct. 04, 2020 | Jul. 05, 2020 | Apr. 05, 2020 | Jun. 30, 2019 | Mar. 31, 2019 | Oct. 04, 2020 | Sep. 29, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |
Stock options outstanding (in shares) | 0 |  |  |  |  | 0 |
Stock options granted in period (in shares) |  |  |  |  |  | 0 | 0
Stock options exercised in period (in shares) |  |  |  |  |  | 7,500 | 10,000
Stock options forfeited in period (in shares) |  |  |  |  |  | 20,000 | 5,000
Share-based Payment Arrangement, Option |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |
Stock compensation expense |  |  |  |  |  | $ 0 | $ 0
Restricted Stock |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |
Stock compensation expense |  |  |  |  |  | $ 600,000 | $ 2,500,000
Stock options granted (in shares) |  |  |  |  |  | 308,100 | 224,000
Unrecognized compensation costs related to unvested restricted stock | $ 3,800,000 |  |  |  |  | $ 3,800,000 |
Restricted Stock | Minimum |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |
Stock options, vesting period |  |  |  |  |  | 1 year |
Restricted Stock | Maximum |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |
Stock options, vesting period |  |  |  |  |  | 3 years |
Performance Shares |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |
Stock compensation expense |  |  |  |  |  | $ (2,000,000.0) | $ 4,000,000.0
Stock options granted (in shares) |  |  |  |  |  | 263,700 |
Number of shares that may be issued in settlement of the performance shares to the award recipient, upper limit (percentage) |  |  |  |  |  | 200.00% |
Unrecognized compensation expense | 6,900,000 |  |  |  |  | $ 6,900,000 |
Performance Shares | Minimum |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |
Stock options, vesting period |  |  |  |  |  | 1 year |
Performance Shares | Maximum |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |
Stock options, vesting period |  |  |  |  |  | 3 years |
Restricted Stock and Performance Shares |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |
Compensation expense, tax benefit |  |  |  |  |  | $ 300,000 |
Common Stock |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |
tile_ForfeituresAndCompensationExpenseRelatedToStockAwardsValue | $ 1,000 | $ 3,000 | $ 25,000 | $ 3,000 | $ 22,000 |  |

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- Definition Amount of cost to be recognized for nonvested award under share-based payment arrangement. Excludes share and unit options. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (i) -URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901 + Details
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- Definition The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(2)(iii)(1) -URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901 + Details
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