|
Stock Plans and Stock Based Compensation (Details) (USD $)
|
3 Months Ended |
12 Months Ended |
|
Sep. 30, 2011
|
Dec. 31, 2013
|
| Number of options: |
|
|
| Number of Options granted |
155,725 |
110,075 |
|
Stock Options And Stock Appreciation Rights
|
|
|
| Number of options: |
|
|
| Number of Options outstanding, beginning |
|
898,868 |
| Number of Options granted |
|
62,420 |
| Number of Options exercised |
|
(218,734) |
| Number of Options forfeited |
|
(19,730) |
| Number of Options outstanding, ending |
|
722,824 |
| Number of Options exercisable |
|
457,532 |
| Weighted Average Exercise Price: |
|
|
| Weighted Average Exercise Price of Options outstanding, beginning |
|
$ 37.66 |
| Weighted Average Exercise Price of Options granted |
|
$ 40.60 |
| Weighted Average Exercise Price of Options exercised |
|
$ 36.74 |
| Weighted Average Exercise Price of Options forfeited |
|
$ 39.51 |
| Weighted Average Exercise Price of Options outstanding, ending |
|
$ 38.14 |
| Weighted Average Exercise Price of Options exercisable |
|
$ 37.45 |
| Weighted Average Remaining Contractual Term: |
|
|
| Weighted Average Remaining Contractual Term of Options outstanding, ending |
|
4 years 9 months 7 days |
| Weighted Average Remaining Contractual Term of Options exercisable |
|
3 years 6 months 7 days |
| Aggregate Intrinsic Value: |
|
|
| Aggregate Intrinsic Value of Options outstanding, ending |
|
$ 9,576,274 |
| Aggregate Intrinsic Value of Options exercisable |
|
$ 6,376,769 |