Goodwill and intangible assets (Schedule of goodwill) (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 27, 2014
Goodwill [Roll Forward]
Goodwill, gross, as of December 31, 2013	$ 3,063,517
Accumulated impairment losses	(1,327,425)
Goodwill, net, as of December 31, 2013	1,736,092
Goodwill recognized or adjusted during the period	5,278
Currency translation during the year	(72,850)
Goodwill, gross, as of September 27, 2014	2,995,945
Accumulated impairment losses	(1,327,425)
Goodwill, net, as of September 27, 2014	1,668,520
Carpet Segment [Member]
Goodwill [Roll Forward]
Goodwill, gross, as of December 31, 2013	199,132
Accumulated impairment losses	(199,132)
Goodwill, net, as of December 31, 2013	0
Goodwill recognized or adjusted during the period
Currency translation during the year
Goodwill, gross, as of September 27, 2014	199,132
Accumulated impairment losses	(199,132)
Goodwill, net, as of September 27, 2014	0
Ceramic Segment [Member]
Goodwill [Roll Forward]
Goodwill, gross, as of December 31, 2013	1,459,812
Accumulated impairment losses	(531,930)
Goodwill, net, as of December 31, 2013	927,882
Goodwill recognized or adjusted during the period	(2,497)
Currency translation during the year	(23,549)
Goodwill, gross, as of September 27, 2014	1,433,766
Accumulated impairment losses	(531,930)
Goodwill, net, as of September 27, 2014	901,836
Laminate and Wood Segment [Member]
Goodwill [Roll Forward]
Goodwill, gross, as of December 31, 2013	1,404,573
Accumulated impairment losses	(596,363)
Goodwill, net, as of December 31, 2013	808,210
Goodwill recognized or adjusted during the period	7,775
Currency translation during the year	(49,301)
Goodwill, gross, as of September 27, 2014	1,363,047
Accumulated impairment losses	(596,363)
Goodwill, net, as of September 27, 2014	$ 766,684