Goodwill and Other intangible assets - Goodwill by reportable business segment (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended			12 Months Ended			12 Months Ended			12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013	Dec. 31, 2012 North America [Member]	Dec. 31, 2011 North America [Member]	Dec. 31, 2013 North America [Member]	Dec. 31, 2012 International [Member]	Dec. 31, 2011 International [Member]	Dec. 31, 2013 International [Member]	Dec. 31, 2012 Sealy [Member]	Dec. 31, 2011 Sealy [Member]	Dec. 31, 2013 Sealy [Member]	Mar. 18, 2013 Sealy [Member]
Goodwill [Line Items]
Beginning balance	$ 213.3		$ 759.6	$ 108.5		$ 107.7	$ 104.8		$ 107.3	$ 0		$ 544.6
Goodwill resulting from acquisition	541.8	2.2		0	0		0	2.2		541.8	0
Foreign currency translation adjustments	1.7	0.6		(1.2)	0.4		0.1	0.2		2.8	0
Ending balance	216.1	213.3	759.6	108.9	108.5	107.7	107.2	104.8	107.3	0	0	544.6
Change in goodwill as a result of acquisition													$ 541.8