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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
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Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
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-Paragraph 18
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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Consolidated Revenue and Long-Lived Assets Information by Geographic Area (Detail) - USD ($) $ in Millions	3 Months Ended				12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Segment Reporting Information [Line Items]
Revenue	$ 865.9	$ 834.9	$ 918.1	$ 865.6	$ 3,484.5	$ 3,334.3	$ 2,972.5
Long-lived assets at December 31	1,581.8				1,581.8	1,668.9	1,165.5
United States
Segment Reporting Information [Line Items]
Revenue					2,009.0	1,814.5	1,626.5
Long-lived assets at December 31	657.5				657.5	657.6	552.3
International
Segment Reporting Information [Line Items]
Revenue					1,475.5	1,519.8	1,346.0
Long-lived assets at December 31	$ 924.3				924.3	1,011.3	613.2
International \| Europe Middle East And Africa (EMEA) [Member]
Segment Reporting Information [Line Items]
Revenue					882.3	952.8	862.8
International \| Americas [Member]
Segment Reporting Information [Line Items]
Revenue					229.0	228.7	197.1
International \| Asia Pacific [Member]
Segment Reporting Information [Line Items]
Revenue					$ 364.2	$ 338.3	$ 286.1