Employee Benefit Plans Employee Benefit Plans (Details) - USD ($) |
3 Months Ended | 12 Months Ended | |||
|---|---|---|---|---|---|
Dec. 31, 2012 |
Dec. 31, 2015 |
Dec. 31, 2013 |
Dec. 31, 2007 |
Jun. 30, 2015 |
|
| Compensation and Retirement Disclosure [Abstract] | |||||
| Eligibility period for 401K savings plan, number of months | 3 months | ||||
| Defined Contribution Plan - maximum participant deferral percent | 60.00% | ||||
| Defined Contribution Plan - employer match per dollar of participant contribution | $ 0.50 | ||||
| Defined Contribution Plan - maximum employer match percentage | 10.00% | ||||
| Defined Contribution Plan - contributions made | $ 900,000 | $ 1,100,000 | $ 1,000,000 | ||
| Deferred Compensation - maximum participant deferral percent | 70.00% | ||||
| Deferred Compensation - maximum director fees and bonuses that may be deferred (percent) | 100.00% | ||||
| Deferred Compensation - mandatory Company contributions as percentage of gross monthly salary (percent) | 10.00% | ||||
| Deferred Compensation - liability under Plan | $ 11,900,000 | $ 12,800,000 | |||