PENSION AND OTHER POSTRETIREMENT BENEFIT PLANS - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Jun. 30, 2011
Defined Benefit Plan Disclosure [Line Items]
Increase in fair value of pension assets	$ 138
Percentage increase in fair value of pension assets	2.90%
Pension asset
Defined Benefit Plan Disclosure [Line Items]
Pension plan adjustment for net funded status	20
Liability for deferred pension
Defined Benefit Plan Disclosure [Line Items]
Pension plan adjustment for net funded status	86
Liability for deferred income taxes
Defined Benefit Plan Disclosure [Line Items]
Pension plan adjustment for net funded status	(38)
Cumulative other comprehensive loss
Defined Benefit Plan Disclosure [Line Items]
Pension plan adjustment for net funded status	(68)
Registered and Non registered Pension Plans | Canada
Defined Benefit Plan Disclosure [Line Items]
Expected contribution to benefit plans during 2011	80
Non-Qualified Pension Plans, Defined Benefit | United States
Defined Benefit Plan Disclosure [Line Items]
Expected contribution to benefit plans during 2011	19
Qualified Pension Plans, Defined Benefit | United States
Defined Benefit Plan Disclosure [Line Items]
Expected contribution to benefit plans during 2011	0
Other Postretirement Benefits | United States And Canada
Defined Benefit Plan Disclosure [Line Items]
Expected contribution to benefit plans during 2011	$ 44