Segment Information - Revenues By Geographic Area (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
Segment Reporting Information [Line Items]
Total consolidated revenues	$ 6,029,955	$ 5,278,176	$ 5,311,393	$ 5,094,378	$ 5,574,431	$ 4,980,201	$ 4,845,338	$ 4,607,618	$ 21,713,902	$ 20,007,588	$ 17,015,126
United States
Segment Reporting Information [Line Items]
Total consolidated revenues									11,510,216	10,549,594	9,152,363
Europe, Middle East and Africa
Segment Reporting Information [Line Items]
Total consolidated revenues									5,908,204	5,667,610	4,942,104
Asia Pacific and Japan
Segment Reporting Information [Line Items]
Total consolidated revenues									3,016,451	2,639,397	1,965,154
Latin America, Mexico and Canada
Segment Reporting Information [Line Items]
Total consolidated revenues									$ 1,279,031	$ 1,150,987	$ 955,505