Share Based Compensation (Narrative) (Details) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock authorized for grant under the Share Incentive Plans	5,650,000
Exercise price per share of options granted, percentage, minimum	100.00%
Additional compensation expense	$ 14.5	$ 33.3	$ 21.9
Unrecognized compensation costs	27.4
Compensation costs expected to be recognized in 2013	10.0
Compensation costs expected to be recognized in 2014	8.3
Weighted average values of grants	$ 43.74	$ 58.22	$ 56.57
Weighted average expected volatility	30.47%	31.00%	30.70%
Weighted average discount rates	1.53%	0.81%	1.65%
Expected lives	5 years 11 months 16 days	5 years 10 months 28 days	5 years 8 months 23 days
Total grant date fair value of restricted stock and restricted stock units vested	3.7	38.1	1.6
Share-based Compensation Arrangement by Share-based Payment Award Accelerated Compensation Cost	3.3	12.2
Aggregate intrinsic value of exercised stock options	10.5	7.0	6.8
Weighted average remaining contractual term for total outstanding stock options	5 years 11 months 19 days
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Exercisable, Weighted Average Remaining Contractual Term	4 years 6 months 11 days
Aggregate intrinsic value of options outstanding	49.3
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Intrinsic Value	$ 33.8
Common Stock, Dividends, Per Share, Cash Paid	$ 0.00	$ 5.00	$ 0.00
Employee Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock authorized for grant under the Share Incentive Plans	600,000
Share-based Compensation Arrangement by Share-based Payment Award, Discount from Market Price, Purchase Date	85.00%
Common stock made available for purchase under the Employee Stock Purchase Plans, offering period, months	6
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number	302,370	180,930
Restricted Stock [Member] \| Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock and restricted stock units vesting period, minimum	1 year
Restricted Stock [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock and restricted stock units vesting period, minimum	5 years
Employee Stock Option [Member] \| Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock and restricted stock units vesting period, minimum	1 year
Employee Stock Option [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock and restricted stock units vesting period, minimum	5 years

Compensation costs expected to be recognized in the next fiscal year.

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Compensation costs expected to be recognized in two years.

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Employee common stock purchase plan offering period.

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Minimum percentage of exercise price per share of options granted to the fair market value of common stock at the date of grant.

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Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

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Aggregate dividends paid during the period for each share of common stock outstanding.

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Unrecognized cost of unvested share-based compensation awards.

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Additional share-based compensation cost recognized as a result of an occurrence of an event that accelerates its recognition.

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Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Discount rate from fair value on purchase date that participants pay for shares.

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The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

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Fair value of share-based awards for which the grantee gained the right by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash.

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

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Weighted average expected volatility rate of share-based compensation awards.

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The maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested).

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Amount of difference between fair value of the underlying shares reserved for issuance and exercise price of vested portions of options outstanding and currently exercisable.

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Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares.

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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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Amount by which the current fair value of the underlying stock exceeds the exercise price of options outstanding.

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Weighted average remaining contractual term for option awards outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Weighted average remaining contractual term for fully vested and expected to vest options that are exercisable or convertible, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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