Summary of Operations by Segment (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Segment Reporting Information [Line Items]
Revenue	$ 882.5	$ 792.1	$ 2,450.6	$ 2,460.6
Operating income (loss)	76.6	24.0	72.5	63.6
Operating Segments
Segment Reporting Information [Line Items]
Revenue	882.5	792.1	2,450.6	2,460.6
Operating income (loss)	92.2	44.9	119.1	129.2
Corporate
Segment Reporting Information [Line Items]
Operating income (loss)	(15.6)	(20.9)	(46.6)	(65.6)
Corporate | Intersegment Eliminations
Segment Reporting Information [Line Items]
Revenue	(35.4)	(22.3)	(58.8)	(56.5)
Corporate | Operating Segments
Segment Reporting Information [Line Items]
Revenue	(35.4)	(22.3)	(58.8)	(56.5)
Services
Segment Reporting Information [Line Items]
Revenue	763.0	720.0	2,166.8	2,182.7
Operating income (loss)	52.7	55.2	94.6	107.0
Services | Intersegment Eliminations
Segment Reporting Information [Line Items]
Revenue		0.4	0.3	1.3
Services | Operating Segments
Segment Reporting Information [Line Items]
Revenue	763.0	720.4	2,167.1	2,184.0
Technology
Segment Reporting Information [Line Items]
Revenue	119.5	72.1	283.8	277.9
Operating income (loss)	39.5	(10.3)	24.5	22.2
Technology | Intersegment Eliminations
Segment Reporting Information [Line Items]
Revenue	35.4	21.9	58.5	55.2
Technology | Operating Segments
Segment Reporting Information [Line Items]
Revenue	$ 154.9	$ 94.0	$ 342.3	$ 333.1