Shareholders' Equity - Activity in Shareholders' Equity (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended						9 Months Ended
	Oct. 04, 2020	Jul. 05, 2020	Apr. 05, 2020	Sep. 29, 2019	Jun. 30, 2019	Mar. 31, 2019	Oct. 04, 2020	Sep. 29, 2019
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance			$ 368,202				$ 368,202
Net loss	$ 5,913			$ 26,210			(91,545)	$ 62,768
Common Stock, Dividends, Per Share, Declared	$ 0.01	$ 0.01	$ 0.065	$ 0.065	$ 0.065	$ 0.065
Pension liability adjustment	$ (1,471)			$ 1,076			(80)	1,814
Foreign currency translation adjustment	23,402			(18,585)			24,317	(19,539)
Cash flow hedge unrealized gain (loss)	864			$ (941)			(5,627)	$ (8,914)
Balance	$ 287,020						$ 287,020
Common Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance (in shares)	58,544	58,488	58,416	58,433	60,016	59,508	58,416	59,508
Balance	$ 5,854	$ 5,849	$ 5,842	$ 5,843	$ 6,002	$ 5,951	$ 5,842	$ 5,951
Stock issuances under employee plans (shares)	7	12	220		2	509
Stock issuances under employee plans	$ 1	$ 1	$ 22		$ 0	$ 51
Other issuances of common stock (in shares)	127	70	107		(1)	224
Other issuances of common stock	$ 13	$ 7	$ 10		$ 0	$ 22
Forfeitures and compensation expense related to stock awards	$ (1)	$ (3)	$ (25)		$ (3)	$ (22)
Stock Repurchased and Retired During Period, Shares					(1,556)
Stock Repurchased and Retired During Period, Value					$ (156)
tile_ForfeituresAndCompensationExpenseRelatedToStockAwardsShares	(8)	(26)	(255)		(28)	(225)
Balance (in shares)	58,670	58,544	58,488	58,433	58,433	60,016	58,670	58,433
Balance	$ 5,867	$ 5,854	$ 5,849	$ 5,843	$ 5,843	$ 6,002	$ 5,867	$ 5,843
ADDITIONAL PAID-IN CAPITAL
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance	246,323	246,378	250,306	247,221	270,655	270,269	250,306	270,269
Stock issuances under employee plans	(1)	(1)	197		6	379
Other issuances of common stock	(15)	2,294	1,720		0	3,900
Unamortized stock compensation expense related to restricted stock awards	2	(2,300)	(1,731)		52	(3,922)
Forfeitures and compensation expense related to stock awards	703	(48)	(4,114)	1,303	1,506	29
Stock Repurchased and Retired During Period, Value					(24,998)
Balance	247,012	246,323	246,378	248,524	247,221	270,655	247,012	248,524
RETAINED EARNINGS
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance	184,206	180,082	286,056	251,009	225,373	222,214	286,056	222,214
Net loss	5,913	4,709	(102,167)	26,210	29,499	7,059
Balance	189,533	184,206	180,082	273,421	251,009	225,373	189,533	273,421
Cash dividends declared, $0.065 per common share	(586)	(585)	(3,807)	(3,798)	(3,863)	(3,900)
PENSION LIABILITY
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance	(55,309)	(54,967)	(56,700)	(42,872)	(43,701)	(43,610)	(56,700)	(43,610)
Pension liability adjustment	(1,471)	(342)	1,733	1,076	829	(91)
Balance	(56,780)	(55,309)	(54,967)	(41,796)	(42,872)	(43,701)	(56,780)	(41,796)
FOREIGN CURRENCY TRANSLATION ADJUSTMENT
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance	(112,224)	(128,384)	(113,139)	(102,441)	(106,690)	(101,487)	(113,139)	(101,487)
Foreign currency translation adjustment	23,402	16,160	(15,245)	(18,585)	4,249	(5,203)
Balance	(88,822)	(112,224)	(128,384)	(121,026)	(102,441)	(106,690)	(88,822)	(121,026)
CASH FLOW HEDGE
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance	(10,654)	(10,303)	(4,163)	(6,647)	(1,980)	1,326	(4,163)	1,326
Cash flow hedge unrealized gain (loss)	864	(351)	(6,140)	(941)	(4,667)	(3,306)
Balance	$ (9,790)	$ (10,654)	$ (10,303)	$ (7,588)	$ (6,647)	$ (1,980)	$ (9,790)	$ (7,588)