Stock-Based Compensation (Stock Options, by Exercise Price) (Details) - $ / shares
|
12 Months Ended |
|
|
Dec. 31, 2015 |
Dec. 31, 2014 |
Dec. 31, 2013 |
| Stock Options, Exercise Price Range [Line Items] |
|
|
|
| Options vested and expected to vest, end of year (shares) |
53,284
|
63,598
|
82,937
|
| Options vested and expected to vest, Weighted Average Exercise Price (in usd per share) |
$ 80.00
|
$ 94.33
|
$ 104.26
|
| Options available for future grants (shares) |
243,331
|
233,017
|
|
| Range of grant price, $80.00 |
|
|
|
| Stock Options, Exercise Price Range [Line Items] |
|
|
|
| Range of grant price, lower range limit (in usd per share) |
$ 80.00
|
|
|
| Range of grant price, upper range limit (in usd per share) |
$ 80.00
|
|
|
| Prior Plans |
|
|
|
| Stock Options, Exercise Price Range [Line Items] |
|
|
|
| Options outstanding, number of options outstanding at end of period (shares) |
53,284
|
|
|
| Options exercisable, number exercisable options at end of period (shares) |
27,197
|
|
|
| Options vested and expected to vest, end of year (shares) |
53,284
|
|
|
| Prior Plans | Range of grant price, $80.00 |
|
|
|
| Stock Options, Exercise Price Range [Line Items] |
|
|
|
| Options outstanding, number of options outstanding at end of period (shares) |
53,284
|
|
|
| Options outstanding, weighted average remaining contractual life (years) |
4 years 22 days
|
|
|
| Options outstanding, weighted average exercise price (in usd per share) |
$ 80.00
|
|
|
| Options exercisable, number exercisable options at end of period (shares) |
27,197
|
|
|
| Options exercisable, weighted average exercise price (in usd per share) |
$ 80.00
|
|
|
| Options vested and expected to vest, end of year (shares) |
53,284
|
|
|
| Options vested and expected to vest, Weighted Average Remaining Contractual Life |
4 years 22 days
|
|
|
| Options vested and expected to vest, Weighted Average Exercise Price (in usd per share) |
$ 80.00
|
|
|