Cash Flow Activities (Detail) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
Net (increase) decrease in operating working capital other than cash and cash equivalents:
(Increase) decrease in accounts receivable	$ (219,802)	$ 292,226
Increase in inventories	(2,313)	(96,612)
Increase in prepaid expenses	(116,276)	(118,139)
Decrease in deferred income tax assets	72,652	22,690
Increase (decrease) in accounts payable and accrued liabilities	182,903	(248,040)
Increase in current income tax liabilities	147,980	44,530
Total	65,144	(103,345)	[1]
Supplementary disclosures:
Cash income taxes paid	196,923	326,727
Interest paid, net of amounts capitalized	$ 25,010	$ 8,657

[1] Reclassified to conform to current presentation.