Share-Based Payments and Other Compensation - Deferred Compensation (Details) - Non-management Director - Restricted Stock Units (RSUs) - Director Deferral Program - shares |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2017 |
Dec. 31, 2016 |
Dec. 31, 2015 |
|
| Deferred compensation | |||
| Maximum percentage of qualified remuneration | 100.00% | ||
| Stock units distributed as shares | 0 | 0 | 0 |
| Stock units outstanding | 76,611 | 60,955 | 50,376 |
| X | ||||||||||
- Definition The percentage of annual retainer fees, committee fees and/or chairperson fees allowed to be deferred. No definition available.
|
| X | ||||||||||
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available.
|
| X | ||||||||||
- Definition Number of shares issued pursuant to the terms of a deferred compensation arrangement. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Number of equity instruments other than options outstanding, including both vested and non-vested instruments. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Details
|
| X | ||||||||||
- Details
|
| X | ||||||||||
- Details
|