|
Stock Plans (Details 2) (USD $)
|
12 Months Ended |
|
Dec. 31, 2011
year
|
| Options Outstanding |
|
| Number Outstanding (in shares) |
2,484,844 |
| Weighted Average Remaining Contractual Life (in years) |
7.57 |
| Weighted Average Exercise Price (in dollars per share) |
$ 17.79 |
| Options Exercisable |
|
| Number Exercisable (in shares) |
993,281 |
| Weighted Average Exercise Price (in dollars per share) |
$ 16.37 |
|
Range of exercise prices from $5.00 to $12.49
|
|
| Stock options by exercise price range |
|
| Exercise prices, low end of range (in dollars per share) |
$ 5.00 |
| Exercise prices, high end of range (in dollars per share) |
$ 12.49 |
| Options Outstanding |
|
| Number Outstanding (in shares) |
519,396 |
| Weighted Average Remaining Contractual Life (in years) |
5.52 |
| Weighted Average Exercise Price (in dollars per share) |
$ 8.38 |
| Options Exercisable |
|
| Number Exercisable (in shares) |
264,698 |
| Weighted Average Exercise Price (in dollars per share) |
$ 7.19 |
|
Range of exercise prices from $12.50 to $14.99
|
|
| Stock options by exercise price range |
|
| Exercise prices, low end of range (in dollars per share) |
$ 12.50 |
| Exercise prices, high end of range (in dollars per share) |
$ 14.99 |
| Options Outstanding |
|
| Number Outstanding (in shares) |
513,422 |
| Weighted Average Remaining Contractual Life (in years) |
6.78 |
| Weighted Average Exercise Price (in dollars per share) |
$ 14.10 |
| Options Exercisable |
|
| Number Exercisable (in shares) |
386,413 |
| Weighted Average Exercise Price (in dollars per share) |
$ 14.09 |
|
Range of exercise prices from $15.00 to $24.99
|
|
| Stock options by exercise price range |
|
| Exercise prices, low end of range (in dollars per share) |
$ 15.00 |
| Exercise prices, high end of range (in dollars per share) |
$ 24.99 |
| Options Outstanding |
|
| Number Outstanding (in shares) |
1,182,516 |
| Weighted Average Remaining Contractual Life (in years) |
8.84 |
| Weighted Average Exercise Price (in dollars per share) |
$ 20.11 |
| Options Exercisable |
|
| Number Exercisable (in shares) |
209,670 |
| Weighted Average Exercise Price (in dollars per share) |
$ 20.84 |
|
Range of exercise prices from $25.00 to $34.99
|
|
| Stock options by exercise price range |
|
| Exercise prices, low end of range (in dollars per share) |
$ 25.00 |
| Exercise prices, high end of range (in dollars per share) |
$ 34.99 |
| Options Outstanding |
|
| Number Outstanding (in shares) |
155,002 |
| Weighted Average Remaining Contractual Life (in years) |
7.90 |
| Weighted Average Exercise Price (in dollars per share) |
$ 28.38 |
| Options Exercisable |
|
| Number Exercisable (in shares) |
70,501 |
| Weighted Average Exercise Price (in dollars per share) |
$ 28.06 |
|
Range of exercise prices from $35.00 to $140.00
|
|
| Stock options by exercise price range |
|
| Exercise prices, low end of range (in dollars per share) |
$ 35.00 |
| Exercise prices, high end of range (in dollars per share) |
$ 140.00 |
| Options Outstanding |
|
| Number Outstanding (in shares) |
114,508 |
| Weighted Average Remaining Contractual Life (in years) |
6.88 |
| Weighted Average Exercise Price (in dollars per share) |
$ 38.69 |
| Options Exercisable |
|
| Number Exercisable (in shares) |
61,999 |
| Weighted Average Exercise Price (in dollars per share) |
$ 41.38 |