Segment Results for Reportable Segments and Corporate Activities (Parenthetical) (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Segment Reporting Disclosure [Line Items]
Amortization associated with deferred acquisition costs	$ 1,024.5	$ 1,042.0	$ 973.5