Goodwill and intangible assets (Schedule of goodwill) (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 28, 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 during the period	5,278
Currency translation during the year	(10,657)
Goodwill, gross, as of June 28, 2014	3,058,138
Accumulated impairment losses	(1,327,425)
Goodwill, net, as of June 28, 2014	1,730,713
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 during the period
Currency translation during the year
Goodwill, gross, as of June 28, 2014	199,132
Accumulated impairment losses	(199,132)
Goodwill, net, as of June 28, 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 during the period	(2,497)
Currency translation during the year	(4,768)
Goodwill, gross, as of June 28, 2014	1,452,547
Accumulated impairment losses	(531,930)
Goodwill, net, as of June 28, 2014	920,617
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 during the period	7,775
Currency translation during the year	(5,889)
Goodwill, gross, as of June 28, 2014	1,406,459
Accumulated impairment losses	(596,363)
Goodwill, net, as of June 28, 2014	$ 810,096