Summary of Significant Accounting Policies (Details 2) - shares shares in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2014 |
Dec. 31, 2013 |
Dec. 31, 2012 |
|
| Stock Options, SARs, PSARs, Restricted Shares, and RSUs [Member] | |||
| Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | |||
| Aggregate number of shares excluded from computation of EPS | 39.1 | 40.3 | 19.7 |
| Performance Shares [Member] | |||
| Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | |||
| Aggregate number of shares excluded from computation of EPS | 5.4 | 3.7 | 3.0 |
| Obligations That May Be Settled in Cash or Shares [Member] | |||
| Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | |||
| Aggregate number of shares excluded from computation of EPS | 2.6 | 2.6 | 7.3 |