Goodwill and Intangible Assets (Narrative) (Detail) $ in Millions	3 Months Ended	12 Months Ended
	Sep. 30, 2016 USD ($) Segment	Dec. 31, 2015 USD ($)
Goodwill And Intangible Assets [Line Items]
Number of reporting units | Segment	7
Estimated cost of capital, minimum	10.00%
Estimated cost of capital, maximum	12.50%
Estimated cost of capital, weighted	10.80%
Hypothetical decrease to fair values of each reporting unit		10.00%
Net intangible assets	$ 302.1	$ 317.1
Intangibles with indefinite useful lives	27.6
Estimated amortization expense for intangible assets, current year	7.8
Estimated amortization expense for intangible assets, year 2015	29.8
Estimated amortization expense for intangible assets, year 2016	27.0
Estimated amortization expense for intangible assets, year 2017	24.3
Estimated amortization expense for intangible assets, year 2018	21.2
Estimated amortization expense for intangible assets, year 2019 and thereafter	$ 164.4