Goodwill and intangible assets (Narrative)(Details) (Details) (USD $) In Thousands, unless otherwise specified	Jun. 29, 2013	Dec. 31, 2012	May 03, 2013 Spano Invest NV [Member]	Jan. 10, 2013 Pergo [Member]	Apr. 03, 2013 Marrazzi Group [Member]
Goodwill [Line Items]
Goodwill	$ 1,690,622	$ 1,385,771	$ 35,857	$ 24,501	$ 262,613

Carrying amount as of the balance sheet date, which is the cumulative amount paid and (if applicable) the fair value of any noncontrolling interest in the acquiree, adjusted for any amortization recognized prior to the adoption of any changes in generally accepted accounting principles (as applicable) and for any impairment charges, in excess of the fair value of net assets acquired in one or more business combination transactions.

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+ Details