Long-Term Obligations (Details) - USD ($) $ in Millions |
3 Months Ended | ||
|---|---|---|---|
Feb. 06, 2018 |
Mar. 31, 2018 |
Dec. 31, 2017 |
|
| Long-Term Obligations | |||
| Maximum borrowing capacity | $ 40.0 | $ 30.0 | |
| Revolving credit facility | |||
| Long-Term Obligations | |||
| Outstanding borrowings | $ 0.0 | ||
| Commitment fee for quarterly unused capacity (as a percent) | 0.25% | ||
| Unused line of credit fee threshold | $ 15.0 | ||
| Minimum | Prime Rate | |||
| Long-Term Obligations | |||
| Basis spread on variable rate (as a percent) | 0.00% | ||
| Minimum | LIBOR | |||
| Long-Term Obligations | |||
| Basis spread on variable rate (as a percent) | 2.50% | ||
| Maximum | Prime Rate | |||
| Long-Term Obligations | |||
| Basis spread on variable rate (as a percent) | 0.25% | ||
| Maximum | LIBOR | |||
| Long-Term Obligations | |||
| Basis spread on variable rate (as a percent) | 2.75% |