Status of Outstanding Restricted Stock Unit Awards Under Twenty Twelve Plan and Twenty Zero Two Plan (Detail) - Restricted Stock Unit Awards $ in Millions	12 Months Ended
	Dec. 31, 2015 USD ($) shares
NUMBER
Restricted Stock Unit Awards Outstanding, at beginning of the year (in shares)	3,381,909
Granted (in shares)	970,317
Distributed (in shares)	(831,661)
Forfeited (in shares)	(117,595)
Stock and Stock Unit Awards Outstanding, at the end of year (in shares)	3,402,970
Units Convertible, at the end of year (in shares)	180,751
AGGREGATE INTRINSIC VALUE
Restricted Stock Unit Awards Outstanding, at beginning of the year | $	$ 227.9
Stock and Stock Unit Awards Outstanding, at the end of year | $	245.3
Units Convertible, at the end of year | $	$ 13.0