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Share-Based Payments (Details Textual) $ / shares in Units, $ in Millions | 12 Months Ended |
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Dec. 31, 2017 USD ($) Plan Increment $ / shares shares | Dec. 31, 2016 USD ($) $ / shares shares | Dec. 31, 2015 USD ($) $ / shares shares | Dec. 31, 2013 Increment | Jun. 30, 2017 shares
Share-based Compensation Arrangement by Share-based Payment Award |  |  |  |  |  |  |
Shares issued under ESPP |  | 6,200,000 |  |  |  |  |
Share-Based Payments (Textual) |  |  |  |  |  |  |
Unrecognized compensation cost related to unvested share-based compensation | $ |  | $ 168.0 |  |  |  |  |
Weighted-average period to recognize the cost of unvested awards |  | 1 year 11 months |  |  |  |  |
Number of share-based compensation plans pursuant to which awards are currently being made | Plan |  | 3 |  |  |  |  |
Number of shares granted under stock options |  | 0 |  | 0 | 0 |  |
Total intrinsic value of options exercised | $ |  | $ 3.4 |  | $ 10.4 | $ 38.0 |  |
Aggregate intrinsic values of options outstanding | $ |  | $ 11.1 |  |  |  |  |
Weighted average remaining contractual term for options outstanding |  | 1 year 4 months |  |  |  |  |
Market stock units |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award |  |  |  |  |  |  |
Number of equal annual increments | Increment |  | 3 |  |  |  | 4 |
Percentage of earnings of the target number of units granted based on actual stock performance (Minimum) |  | 0.00% |  |  |  | 0.00% |
Percentage of earnings of the target number of units granted based on actual stock performance (Maximum) |  | 200.00% |  |  |  | 150.00% |
Number of shares granted | [1] | 94,000 |  |  |  |  |
Number of days for calculation of average closing stock price |  | 30 days |  |  |  | 60 days |
Total fair value of vested awards | $ |  | $ 31.4 |  | $ 39.3 | $ 109.0 |  |
Weighted average grant date fair value | $ / shares |  | $ 382.59 | [1] | $ 328.03 | $ 493.43 |  |
Cash settled performance units |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award |  |  |  |  |  |  |
Number of equal annual increments | Increment |  | 3 |  |  |  |  |
Percentage of earnings of the target number of units granted based on actual stock performance (Minimum) |  | 0.00% |  |  |  |  |
Percentage of earnings of the target number of units granted based on actual stock performance (Maximum) |  | 200.00% |  |  |  |  |
Number of shares granted | [2] | 83,000,000 |  |  |  |  |
Number of days for calculation of average closing stock price |  | 30 days |  |  |  | 60 days |
Cash in settlement of CSPS awards upon vesting | $ |  | $ 16.6 |  | $ 31.9 | $ 79.8 |  |
Performance units |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award |  |  |  |  |  |  |
Number of equal annual increments | Increment |  | 3 |  |  |  |  |
Percentage of earnings of the target number of units granted based on actual stock performance (Minimum) |  | 0.00% |  |  |  |  |
Percentage of earnings of the target number of units granted based on actual stock performance (Maximum) |  | 200.00% |  |  |  |  |
Number of shares granted | [2] | 40,000,000 |  |  |  |  |
Number of days for calculation of average closing stock price |  | 30 days |  |  |  |  |
Cash in settlement of CSPS awards upon vesting | $ |  | $ 11.5 |  | 8.1 | $ 12.4 |  |
PUs converted to share settlements |  |  |  |  | 32,000 |  |
Time-vested restricted stock units |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award |  |  |  |  |  |  |
Number of shares granted | [3] | 464,000 |  |  |  |  |
Total fair value of vested awards | $ |  | $ 100.0 |  | $ 104.6 | $ 239.7 |  |
Weighted average grant date fair value | $ / shares |  | $ 293.41 | [3] | $ 268.52 | $ 388.88 |  |
Director | Time-vested restricted stock units |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award |  |  |  |  |  |  |
Number of shares granted | [3] | 11,000 |  |  |  |  |
Settlement of PUs | Performance units |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award |  |  |  |  |  |  |
PUs converted to share settlements |  |  |  |  | 11,000 |  |
Directors Plan |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award |  |  |  |  |  |  |
Total number of shares of common stock for issuance |  | 1,600,000 |  |  |  |  |
Ratio of total number of shares reserved under the plan |  | 1.5-to-1 |  |  |  |  |
2017 Omnibus Equity Plan [Member] |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award |  |  |  |  |  |  |
Ratio of total number of shares reserved under the plan |  | 1.5-to-1 |  |  |  |  |
Omnibus Plan number of shares authorized |  |  |  |  |  |  | 8,000,000
Attainment Of Performance Criteria in 2013 | Market stock units |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award |  |  |  |  |  |  |
Number of shares granted | [1] | 9,000 |  |  |  |  |
[1] | MSUs granted in 2017 include approximately 9,000 MSUs issued in 2017 based upon the attainment of performance criteria set for 2013, in relation to awards granted in that year. MSUs granted during 2017 also include awards granted in conjunction with our annual awards made in February 2017 and MSUs granted in conjunction with the hiring of employees. These grants reflect the target number of shares eligible to be earned at the time of grant. MSUs granted in 2017 reflect an adjustment based upon the final performance multiplier in relation to shares granted in 2016, 2015 and 2014.
[2] | CSPUs granted in 2017 include awards granted in conjunction with our annual awards made in February 2017 and CSPUs granted in conjunction with the hiring of employees. These grants reflect the target number of shares eligible to be earned at the time of grant. CSPUs granted in 2017 also include CSPUs issued in 2017 based upon the attainment of performance criteria set for 2016 in relation to shares granted in 2016.
[3] | RSUs granted in 2017 primarily represent RSUs granted in conjunction with our annual awards made in February 2017 and awards made in conjunction with the hiring of new employees. RSUs granted in 2017 also include approximately 11,000 RSUs granted to our Board of Directors.

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- Definition 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). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a)(3) -URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901 + Details
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