Goodwill and Other Intangible Assets (Schedule of goodwill) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Mar. 31, 2018
Goodwill [Line Items]
Goodwill, impairment loss	$ 0
Goodwill [Roll Forward]
Goodwill, beginning balance	3,798,884,000	$ 3,601,851,000
Accumulated impairments losses, beginning balance	(1,327,425,000)	(1,327,425,000)
Goodwill	2,520,966,000	2,471,459,000	$ 2,274,426,000
Goodwill recognized during the year		119,738,000	60,493,000
Currency translation during the year		(70,231,000)	136,540,000
Goodwill, ending balance	3,848,391,000	3,798,884,000	3,601,851,000
Accumulated impairments losses, ending balance	(1,327,425,000)	(1,327,425,000)	(1,327,425,000)
Goodwill, net, ending balance	2,520,966,000	2,471,459,000	2,274,426,000
Global Ceramic
Goodwill [Roll Forward]
Goodwill recognized during the year	19,821,000
Currency translation during the year	(22,706,000)
Flooring NA
Goodwill [Roll Forward]
Goodwill recognized during the year	4,434,000
Currency translation during the year	0
Flooring ROW
Goodwill [Roll Forward]
Goodwill				$ 12,874,000
Goodwill recognized during the year	95,483,000
Currency translation during the year	(47,525,000)
Goodwill, net, ending balance				$ 12,874,000
Operating segments | Global Ceramic
Goodwill [Roll Forward]
Goodwill, beginning balance	1,567,872,000	1,482,226,000
Accumulated impairments losses, beginning balance	(531,930,000)	(531,930,000)
Goodwill	1,033,057,000	1,035,942,000	950,296,000
Goodwill recognized during the year			60,493,000
Currency translation during the year			25,153,000
Goodwill, ending balance	1,564,987,000	1,567,872,000	1,482,226,000
Accumulated impairments losses, ending balance	(531,930,000)	(531,930,000)	(531,930,000)
Goodwill, net, ending balance	1,033,057,000	1,035,942,000	950,296,000
Operating segments | Flooring NA
Goodwill [Roll Forward]
Goodwill, beginning balance	869,764,000	869,764,000
Accumulated impairments losses, beginning balance	(343,054,000)	(343,054,000)
Goodwill	531,144,000	526,710,000	526,710,000
Goodwill recognized during the year			0
Currency translation during the year			0
Goodwill, ending balance	874,198,000	869,764,000	869,764,000
Accumulated impairments losses, ending balance	(343,054,000)	(343,054,000)	(343,054,000)
Goodwill, net, ending balance	531,144,000	526,710,000	526,710,000
Operating segments | Flooring ROW
Goodwill [Roll Forward]
Goodwill, beginning balance	1,361,248,000	1,249,861,000
Accumulated impairments losses, beginning balance	(452,441,000)	(452,441,000)
Goodwill	956,765,000	908,807,000	797,420,000
Goodwill recognized during the year			0
Currency translation during the year			111,387,000
Goodwill, ending balance	1,409,206,000	1,361,248,000	1,249,861,000
Accumulated impairments losses, ending balance	(452,441,000)	(452,441,000)	(452,441,000)
Goodwill, net, ending balance	$ 956,765,000	$ 908,807,000	$ 797,420,000