Net gain on sale of vascular operations - Disc Ops - Schedule of Information Related to Sale of Vascular Operation (Parenthetical) (Detail) (Vascular operation [Member], USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012
Vascular operation [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Settlement of litigation claim by former patent holders	$ 3.5