Segment reporting (Summary of segment information) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 29, 2014 segment	Mar. 30, 2013	Dec. 31, 2013
Segment Reporting Information [Line Items]
Net sales	$ 1,813,095	$ 1,486,815
Intersegment sales	(24,933)	(24,875)
Operating income (loss)	130,735	86,842
Assets	8,681,488		8,494,177
Number of reporting segments	3
Carpet Segment [Member]
Segment Reporting Information [Line Items]
Net sales	674,926	695,334
Operating income (loss)	34,271	25,238
Assets	1,920,937		1,786,085
Ceramic Segment [Member]
Segment Reporting Information [Line Items]
Net sales	695,094	411,881
Operating income (loss)	60,659	29,976
Assets	3,782,006		3,787,785
Laminate and Wood Segment [Member]
Segment Reporting Information [Line Items]
Net sales	468,008	404,475
Operating income (loss)	44,119	38,693
Assets	2,788,839		2,716,759
Corporate and Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Operating income (loss)	(8,314)	(7,065)
Assets	$ 189,706		$ 203,548