Noncash Operating Working Capital (Increased) Decreased (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010		Dec. 31, 2009
Accounts receivable	$ (43,630)	$ (4,363)		$ (402,481)
Inventories	(59,413)	(28,231)		(114,569)
Prepaid expenses	20,548	14,567		7,209
Deferred income tax assets	8,488	(80,073)		14,772
Accounts payable and accrued liabilities	(478,029)	766,067		365,257
Current income tax liabilities	(273,118)	(28,401)		(64,878)
Net (increase) decrease in noncash operating working capital	$ (825,154)	$ 639,566	[1]	$ (194,690)	[1]

[1] Reclassified to conform to current presentation.