Draws on Credit Facility that are Designated as Net Investments in International Operations (Parenthetical) (Detail) (Canadian Dollars) In Millions, unless otherwise specified	Mar. 31, 2013 USD ($)		Mar. 31, 2013 CAD		Mar. 31, 2013 Not Designated as Hedging Instrument USD ($)
Derivative [Line Items]
Draws on the line of credit	$ 31	[1]	31	[1]	$ 74

[1] We have drawn an additional $74 million on the credit facility in Canadian dollars that has not been designated as a hedging instrument.