Goodwill and intangible assets (Schedule of goodwill) (Details) $ in Thousands	9 Months Ended
	Oct. 03, 2015 USD ($)
Goodwill [Roll Forward]
Goodwill, gross, beginning balance	$ 2,931,777
Accumulated impairment losses	(1,327,425)
Goodwill, net, beginning balance	1,604,352
Goodwill recognized or adjusted during the period	733,664
Currency translation during the year	(57,294)
Goodwill, gross, ending balance	3,608,147
Accumulated impairment losses	(1,327,425)
Goodwill, net, ending balance	2,280,722
Global Ceramic Segment [Member]
Goodwill [Roll Forward]
Goodwill, gross, beginning balance	1,395,132
Accumulated impairment losses	(531,930)
Goodwill, net, beginning balance	863,202
Goodwill recognized or adjusted during the period	100,316
Currency translation during the year	(12,579)
Goodwill, gross, ending balance	1,482,869
Accumulated impairment losses	(531,930)
Goodwill, net, ending balance	950,939
Flooring NA Segment [Member]
Goodwill [Roll Forward]
Goodwill, gross, beginning balance	538,515
Accumulated impairment losses	(343,054)
Goodwill, net, beginning balance	195,461
Goodwill recognized or adjusted during the period	319,528
Currency translation during the year	0
Goodwill, gross, ending balance	858,043
Accumulated impairment losses	(343,054)
Goodwill, net, ending balance	514,989
Flooring ROW Segment [Member]
Goodwill [Roll Forward]
Goodwill, gross, beginning balance	998,130
Accumulated impairment losses	(452,441)
Goodwill, net, beginning balance	545,689
Goodwill recognized or adjusted during the period	313,820
Currency translation during the year	(44,715)
Goodwill, gross, ending balance	1,267,235
Accumulated impairment losses	(452,441)
Goodwill, net, ending balance	$ 814,794