|
Stock-Based Compensation - Summary of Stock Option Activities in Equity Plan (Details) (USD $)
In Thousands, except Share data, unless otherwise specified
|
3 Months Ended |
|
Mar. 31, 2015
|
| Shares |
|
| Shares, Options outstanding as of beginning of period |
1,234,530 |
| Shares, Granted |
0 |
| Shares, Exercised |
(17,062) |
| Shares, Cancelled |
(1,245) |
| Shares, Options outstanding as of end of period |
1,216,223 |
| Shares, Options exercisable as of end of period |
1,135,076 |
| Weighted- Average Exercise Price |
|
| Weighted-Average Exercise Price, Options outstanding as of beginning of period |
$ 31.10 |
| Weighted-Average Exercise Price, Granted |
$ 0.00 |
| Weighted-Average Exercise Price, Exercised |
$ 26.40 |
| Weighted-Average Exercise Price, Cancelled |
$ 35.23 |
| Weighted-Average Exercise Price, Options outstanding as of end of period |
$ 31.16 |
| Weighted-Average Exercise Price, Options exercisable as of end of period |
$ 30.45 |
| Weighted-Average Remaining Contractual Term and Aggregate Intrinsic Value |
|
| Weighted-Average Remaining Contractual Term, Options outstanding as of end of period |
4 years 11 months 9 days |
| Weighted-Average Remaining Contractual Term, Options exercisable as of end of period |
4 years 9 months 29 days |
| Aggregate Intrinsic Value, Options outstanding as of end of period |
$ 19,178 |
| Aggregate Intrinsic Value, Options exercisable as of end of period |
$ 18,641 |
| Weighted- Average Fair Value |
|
| Weighted-Average Fair Value, Options outstanding as of beginning of period |
$ 12.75 |
| Weighted-Average Fair Value, Granted |
$ 0.00 |
| Weighted-Average Fair Value, Exercised |
$ 10.94 |
| Weighted-Average Fair Value, Cancelled |
$ 14.46 |
| Weighted-Average Fair Value, Options outstanding as of end of period |
$ 12.77 |
| Weighted-Average Fair Value, Options exercisable as of end of period |
$ 12.59 |