| **Stock-based Compensation Plans - Range of Exercise Prices of  Exercisable Stock Options (Details) (USD $)In Millions, except Share data in Thousands, unless otherwise specified** | 12 Months Ended |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------|
||
| $ 21.02 - $ 31.81                                                                                                                                                                    |            |
| **Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]**                                                                          |            |
| Lower Exercise Price Range Limit                                                                                                                                                     | $ 21.02         |
| Upper Exercise Price Range Limit                                                                                                                                                     | $ 31.81         |
| **Options Outstanding [Abstract]**                                                                                                                                                   |            |
| Number Outstanding                                                                                                                                                                   | 1,727           |
| Weighted Average Remaining Contractual Life                                                                                                                                          | 4.2             |
| Weighted Average Exercise Price                                                                                                                                                      | $ 23.24         |
| Aggregate Intrinsic Value                                                                                                                                                            | $ 18.4          |
| **Options Exercisable [Abstract]**                                                                                                                                                   |            |
| Number Outstanding                                                                                                                                                                   | 1,122           |
| Weighted Average Remaining Contractual Life                                                                                                                                          | 3.8             |
| Weighted Average Exercise Price                                                                                                                                                      | $ 23.59         |
| Aggregate Intrinsic Value                                                                                                                                                            | 14.1            |
| $ 31.82 - $ 40.92                                                                                                                                                                    |            |
| **Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]**                                                                          |            |
| Lower Exercise Price Range Limit                                                                                                                                                     | $ 32.82         |
| Upper Exercise Price Range Limit                                                                                                                                                     | $ 40.92         |
| **Options Outstanding [Abstract]**                                                                                                                                                   |            |
| Number Outstanding                                                                                                                                                                   | 1,788           |
| Weighted Average Remaining Contractual Life                                                                                                                                          | 3.8             |
| Weighted Average Exercise Price                                                                                                                                                      | $ 37.68         |
| Aggregate Intrinsic Value                                                                                                                                                            | 0.2             |
| **Options Exercisable [Abstract]**                                                                                                                                                   |            |
| Number Outstanding                                                                                                                                                                   | 1,086           |
| Weighted Average Remaining Contractual Life                                                                                                                                          | 2.6             |
| Weighted Average Exercise Price                                                                                                                                                      | $ 38.48         |
| Aggregate Intrinsic Value                                                                                                                                                            | 0.1             |
| $ 40.93 - $ 69.91                                                                                                                                                                    |            |
| **Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]**                                                                          |            |
| Lower Exercise Price Range Limit                                                                                                                                                     | $ 40.93         |
| Upper Exercise Price Range Limit                                                                                                                                                     | $ 69.91         |
| **Options Outstanding [Abstract]**                                                                                                                                                   |            |
| Number Outstanding                                                                                                                                                                   | 1,485           |
| Weighted Average Remaining Contractual Life                                                                                                                                          | 2.2             |
| Weighted Average Exercise Price                                                                                                                                                      | $ 52.24         |
| Aggregate Intrinsic Value                                                                                                                                                            | 0               |
| **Options Exercisable [Abstract]**                                                                                                                                                   |            |
| Number Outstanding                                                                                                                                                                   | 1,260           |
| Weighted Average Remaining Contractual Life                                                                                                                                          | 1.9             |
| Weighted Average Exercise Price                                                                                                                                                      | $ 51.02         |
| Aggregate Intrinsic Value                                                                                                                                                            | $ 0             |

| X                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Exercisable Options, Aggregate Intrinsic Value
+ References
No definition available.
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
shares based compensation, shares authorized under stock option plans, exercise price range, exercisable options, weighted average reamining contractual term
+ References
No definition available.
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| X                                                                                                                                                                                                                                                                                                       |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Stock Options Weighted Average Remaining Contractual Life
+ References
No definition available.
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
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.
+ References
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| X                                                                                                                                                                                                                                                      |
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| X                                                                                                                                                                                                                                    |
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Weighted average exercise price as of the balance sheet date for those equity-based payment arrangements exercisable and outstanding.
+ References
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| X                                                                                                                                                                                                                          |
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The floor of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range.
+ References
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The number of shares reserved for issuance pertaining to the outstanding exercisable stock options as of the balance sheet date in the customized range of exercise prices for which the market and performance vesting condition has been satisfied.
+ References
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The number of shares reserved for issuance pertaining to the outstanding stock options as of the balance sheet date for all option plans in the customized range of exercise prices.
+ References
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The weighted average price as of the balance sheet date at which grantees could acquire the underlying shares with respect to all outstanding stock options which are in the customized range of exercise prices.
+ References
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The ceiling of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range.
+ References
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