Stock and Incentive Programs for Employees and Directors - Schedule of Stock Option Activity (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Shares Under Option
Outstanding at beginning of period	3,847
Exercised	(135)
Cancelled/forfeited/expired	(5)
Outstanding at end of period	3,707	3,847
Vested and expected to vest at end of period	3,701
Exercisable at end of period	1,455
Weighted Average Exercise Price
Outstanding at beginning of period	$ 19.43
Exercised	13.21
Cancelled/forfeited/expired	13.23
Outstanding at end of period	19.66	$ 19.43
Vested and expected to vest at end of period	19.67
Exercisable at end of period	$ 9.22
Weighted Average Remaining Contractual Term (years)
Outstanding	3 years 7 months 6 days	4 years 8 months 12 days
Vested and expected to vest at end of period	3 years 7 months 6 days
Exercisable at end of period	4 years 2 months 12 days
Aggregate Intrinsic Value
Outstanding at beginning of period	$ 12.6
Outstanding at end of period	8.4	$ 12.6
Vested and expected to vest at end of period	8.4
Exercisable at end of period	$ 8.0