Goodwill and intangible assets - Schedule of goodwill (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2018 USD ($)
Goodwill [Roll Forward]
Goodwill, gross, beginning balance	$ 3,798,884
Accumulated impairment losses	(1,327,425)
Goodwill, net, beginning balance	2,471,459
Goodwill recognized during the period	12,548
Currency translation during the period	28,608
Goodwill, gross, ending balance	3,840,040
Accumulated impairment losses	(1,327,425)
Goodwill, net, ending balance	2,512,615
Global Ceramic segment
Goodwill [Roll Forward]
Goodwill, gross, beginning balance	1,567,872
Accumulated impairment losses	(531,930)
Goodwill, net, beginning balance	1,035,942
Goodwill recognized during the period	0
Currency translation during the period	5,100
Goodwill, gross, ending balance	1,572,972
Accumulated impairment losses	(531,930)
Goodwill, net, ending balance	1,041,042
Flooring NA segment
Goodwill [Roll Forward]
Goodwill, gross, beginning balance	869,764
Accumulated impairment losses	(343,054)
Goodwill, net, beginning balance	526,710
Goodwill recognized during the period	0
Currency translation during the period	0
Goodwill, gross, ending balance	869,764
Accumulated impairment losses	(343,054)
Goodwill, net, ending balance	526,710
Flooring ROW segment
Goodwill [Roll Forward]
Goodwill, gross, beginning balance	1,361,248
Accumulated impairment losses	(452,441)
Goodwill, net, beginning balance	908,807
Goodwill recognized during the period	12,548
Currency translation during the period	23,508
Goodwill, gross, ending balance	1,397,304
Accumulated impairment losses	(452,441)
Goodwill, net, ending balance	$ 944,863