Revenue, Properties and Outsourcing Assets by Geographic Segment (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	$ 739.2	$ 882.5	$ 2,225.2	$ 2,450.6
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	359.9	377.3	1,085.8	997.0
United Kingdom
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	92.6	104.6	264.1	327.5
Other International
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	$ 286.7	$ 400.6	$ 875.3	$ 1,126.1