Deferred Payment Obligations (Detail) (USD $) In Millions, unless otherwise specified	0 Months Ended	1 Months Ended
	Jul. 06, 2009	Jan. 26, 2009	Dec. 31, 2012	Sep. 30, 2012	Dec. 31, 2011
Acquired Finite-Lived Intangible Assets [Line Items]
Contractual obligation	$ 4.4	$ 12.0
Finite-lived intangible assets acquired	1.1	3.0
Contractual obligation, due in next twelve months			3.3
Debt, weighted average interest rate				10.20%
Short-term debt				0	1.1
Patents [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Contractual obligation, due in next twelve months			9.0
Debt, weighted average interest rate				13.90%
Short-term debt				$ 0	$ 3.0