Financial Instruments and Fair Value Measurements - Derivative Activity (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Foreign Currency Forwards [Member]
Derivative [Line Items]
Notional amounts at January 1,
New contracts	1,303.8
Acquired contracts
Matured or expired contracts
Notional amounts at December 31,	1,303.8
Interest Rate Swaps [Member]
Derivative [Line Items]
Notional amounts at January 1,	1,496.5	268.1	157.7
New contracts	445.4		155.0
Acquired contracts	71.0	1,337.3
Matured or expired contracts	(698.1)	(108.9)	(44.6)
Notional amounts at December 31,	1,314.8	1,496.5	268.1
Interest Rate Caps [Member]
Derivative [Line Items]
Notional amounts at January 1,
New contracts
Acquired contracts		25.7
Matured or expired contracts		(25.7)
Notional amounts at December 31,