Summary of Operations by Segment (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Segment Reporting Information [Line Items]
Revenue	$ 792.1	$ 877.4	$ 2,460.6	$ 2,727.1
Operating income (loss)	24.0	61.2	63.6	204.6
Operating Segments
Segment Reporting Information [Line Items]
Revenue	792.1	877.4	2,460.6	2,727.1
Corporate
Segment Reporting Information [Line Items]
Operating income (loss)	(20.9)	(25.8)	(65.6)	(64.6)
Corporate | Intersegment Eliminations
Segment Reporting Information [Line Items]
Revenue	(22.3)	(16.2)	(56.5)	(85.8)
Corporate | Operating Segments
Segment Reporting Information [Line Items]
Revenue	(22.3)	(16.2)	(56.5)	(85.8)
Services
Segment Reporting Information [Line Items]
Revenue	720.0	748.0	2,182.7	2,386.7
Operating income (loss)	55.2	44.8	107.0	151.2
Services | Intersegment Eliminations
Segment Reporting Information [Line Items]
Revenue	0.4	0.6	1.3	2.0
Services | Operating Segments
Segment Reporting Information [Line Items]
Revenue	720.4	748.6	2,184.0	2,388.7
Technology
Segment Reporting Information [Line Items]
Revenue	72.1	129.4	277.9	340.4
Operating income (loss)	(10.3)	42.2	22.2	118.0
Technology | Intersegment Eliminations
Segment Reporting Information [Line Items]
Revenue	21.9	15.6	55.2	83.8
Technology | Operating Segments
Segment Reporting Information [Line Items]
Revenue	$ 94.0	$ 145.0	$ 333.1	$ 424.2