Total Revenues Based on Location of the Customer and Long-Lived Assets by Geographic Regions (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended									12 Months Ended
	Dec. 31, 2012		Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Total revenues:
United States										$ 10,183,596	$ 9,488,165	$ 8,298,324
Other locations										1,175,517	848,181	975,981
Total revenues	2,970,876	[1]	2,880,409	2,955,714	2,552,114	2,568,284	2,694,928	2,707,662	2,365,472	11,359,113	10,336,346	9,274,305
United States	281,729					156,471				281,729	156,471	135,312
Other locations	27,991					10,337				27,991	10,337	11,667
Total	$ 309,720					$ 166,808				$ 309,720	$ 166,808	$ 146,979

[1] The quarter ended December 31, 2012 is not comparable to the previous periods shown in this footnote due to certain significant charges or credits related to our recent acquisitions and divestitures.