Consolidated Revenue Information by Geographic Area (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Segment Reporting Information [Line Items]
Revenue	$ 688.5	$ 531.3	$ 1,976.1	$ 1,713.6
United States
Segment Reporting Information [Line Items]
Revenue	375.4	274.3	1,063.2	890.7
International
Segment Reporting Information [Line Items]
Revenue	313.1	257.0	912.9	822.9
International | EMEA
Segment Reporting Information [Line Items]
Revenue	203.3	163.1	590.4	532.1
International | Other
Segment Reporting Information [Line Items]
Revenue	$ 109.8	$ 93.9	$ 322.5	$ 290.8