Goodwill and Other Intangible Assets - Narrative (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Goodwill And Intangible Assets Disclosure [Abstract]
Additions to other intangible assets			$ 106.5
Amortization expense for other intangible assets	$ 19.2	$ 20.5	$ 38.2	$ 38.8