Subsequent event - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2012
Subsequent Event [Line Items]
Business acquisition	$ 55.8	$ 55.8
Business acquisition cost of acquired entity transaction costs	1.8	2.2
LMA International N.V. [Member]
Subsequent Event [Line Items]
Subsequent event description		On October 23, 2012, the Company acquired substantially all of the assets of LMA International N.V., a global provider of laryngeal masks with a portfolio of innovative products used extensively in anesthesia and emergency care. The Company paid $292.2 million in cash as initial consideration for the business.
Business acquisition	292.2	292.2
LMA International N.V. [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Date of acquisition		Oct. 23, 2012
Other Acquisitions [Member]
Subsequent Event [Line Items]
Subsequent event description		On October 23, 2012, in a separate transaction, the Company also acquired the LMA branded laryngeal mask supraglottic airway business and certain other products in the United Kingdom, Ireland and Channel Islands from the shareholders of Intravent Direct Limited and affiliates for $19.9 million in cash. These acquisitions complement the anesthesia product portfolio in the Company's Critical Care division.
Business acquisition	$ 19.9	$ 19.9
Other Acquisitions [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Date of acquisition		Oct. 23, 2012