Stock-Based Compensation - Assumptions Used For Performance Shares (Details) - Performance Shares |
12 Months Ended | ||
|---|---|---|---|
|
Dec. 31, 2019
simulation
$ / shares
|
Dec. 31, 2018
simulation
$ / shares
|
Dec. 31, 2017
simulation
$ / shares
|
|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
| Number of simulations | simulation | 1,000,000 | 1,000,000 | 1,000,000 |
| Expected stock volatility | 52.30% | 40.20% | 41.60% |
| Dividend yield | 0.00% | 0.00% | 0.00% |
| Risk-free interest rate | 1.80% | 2.80% | 1.50% |
| Weighted average grant-date fair value per unit (in dollars per share) | $ / shares | $ 6.68 | $ 22.35 | $ 21.53 |