Stock-Based Compensation Plans (Details 2) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended
Mar. 31, 2014
Amended and Restated 2010 Stock Incentive Plan
Change in options outstanding
Options granted (in shares)	0.6
Assumptions used to estimate fair value of stock options granted during period
Weighted-average expected dividend yield (as a percent)	2.50%
Weighted-average expected volatility (as a percent)	53.20%
Weighted-average risk-free interest rate (as a percent)	2.00%
Weighted-average expected term	6 years 6 months
Weighted-average estimated fair value of stock options granted (in dollars per share)	$ 18.89
Nonqualified Stock Options
Other nonqualified stock option disclosures
Unrecognized compensation costs	$ 11.1
Weighted-average service period over which unrecognized compensation costs will be recognized	1 year 6 months

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Unrecognized cost of unvested share-based compensation awards.

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

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Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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- Definition

The estimated dividend rate (a percentage of the share price) to be paid (expected dividends) to holders of the underlying shares over the option's term.

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Expected term of share-based compensation awards, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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-Section D

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The estimated measure of the percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period.

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The risk-free interest rate assumption that is used in valuing an option on its own shares.

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Net number of share options (or share units) granted during the period.

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The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

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