|
Stock-Based Compensation (Additional Information) (Details) (USD $)
|
3 Months Ended |
|
Mar. 31, 2015
offering_period
|
Mar. 31, 2014
|
| Compensation Related Costs Share Based Payments Disclosure [Line Items] |
|
|
| Options exercised, total intrinsic value |
$ 5,700,000 |
|
| Total amount of cash received from exercise of options |
5,300,000 |
|
| Employee Stock Purchase Plan [Member] |
|
|
| Compensation Related Costs Share Based Payments Disclosure [Line Items] |
|
|
| Compensation expense (income) |
100,000 |
100,000 |
| Employee stock purchase plan, number of offering (offering period) |
2 |
|
| Employee stock purchase plan, offering period (months) |
6 months |
|
| Employee stock purchase plan, purchase price discount (percent) |
15.00% |
|
| Stock Options [Member] |
|
|
| Compensation Related Costs Share Based Payments Disclosure [Line Items] |
|
|
| Stock options, contractual term (years) |
10 years |
|
| Stock-based compensation, approximate forfeitures rate (percent) |
3.00% |
|
| Compensation expense (income) |
100,000 |
100,000 |
| Performance-Based Restricted Stock [Member] |
|
|
| Compensation Related Costs Share Based Payments Disclosure [Line Items] |
|
|
| Stock-based compensation, approximate forfeitures rate (percent) |
7.00% |
|
| Compensation expense (income) |
300,000 |
600,000 |
| Restricted stock award program, measurement period (years) |
3 years |
|
| Expected dividend yield (percent) |
0.00% |
0.00% |
| Restricted stock award program, payment of award as percentage of target (percent) |
118.20% |
|
| Performance-Based Restricted Stock [Member] | Minimum [Member] |
|
|
| Compensation Related Costs Share Based Payments Disclosure [Line Items] |
|
|
| Restricted stock award program, awarded shares as a percentage of the original award amount (percent) |
0.00% |
|
| Performance-Based Restricted Stock [Member] | Maximum [Member] |
|
|
| Compensation Related Costs Share Based Payments Disclosure [Line Items] |
|
|
| Restricted stock award program, awarded shares as a percentage of the original award amount (percent) |
200.00% |
|
| Time Based Restricted Stock [Member] |
|
|
| Compensation Related Costs Share Based Payments Disclosure [Line Items] |
|
|
| Stock-based compensation, approximate forfeitures rate (percent) |
7.00% |
|
| Compensation expense (income) |
1,100,000 |
900,000 |
| Time Based Restricted Stock [Member] | 2012 Grants [Member] |
|
|
| Compensation Related Costs Share Based Payments Disclosure [Line Items] |
|
|
| Restricted stock award program, vesting period (years) |
3 years |
|
| Time Based Restricted Stock [Member] | 2011 Grants [Member] |
|
|
| Compensation Related Costs Share Based Payments Disclosure [Line Items] |
|
|
| Restricted stock award program, vesting period (years) |
4 years |
|
| Deferred Stock Units [Member] |
|
|
| Compensation Related Costs Share Based Payments Disclosure [Line Items] |
|
|
| Compensation expense (income) |
$ 0 |
$ 0 |