Stock-Based Compensation Plans (Details 2) - Nonqualified Stock Options $ / shares in Units, shares in Millions, $ in Millions	9 Months Ended
	Sep. 30, 2015 USD ($) $ / shares shares
Change in options outstanding
Options granted (in shares) | shares	0.6
Assumptions used to estimate fair value of stock options granted during period
Weighted-average expected volatility (as a percent)	52.20%
Weighted-average expected term	6 years 6 months
Weighted-average risk-free interest rate (as a percent)	1.80%
Weighted-average expected dividend yield (as a percent)	2.81%
Weighted-average estimated fair value of stock options granted (in dollars per share)	$ 20.43
Other nonqualified stock option disclosures
Unrecognized compensation costs | $	$ 5.5
Weighted-average service period over which unrecognized compensation costs will be recognized	1 year 4 months 24 days