Cash Flow Activities (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Net (increase) decrease in operating working capital other than cash and cash equivalents:
Decrease in accounts receivable	$ 182,714	$ 69,126
Decrease in inventories	126,826	4,962
Increase in prepaid expenses	(54,119)	(51,508)
Decrease in deferred income tax assets	24,082	5,522
Increase (decrease) in accounts payable and accrued liabilities	(191,616)	229,804
Increase in current income tax liabilities	123,575	43,165
Total	211,462	301,071	[1]
Supplementary disclosures:
Cash income taxes paid	47,877	160,210
Interest paid more (less) than amounts capitalized	$ (10,519)	$ 490

[1] Reclassified to conform to current presentation.