Revenue - Performance Obligations (Details) - USD ($)
$ in Thousands |
Dec. 31, 2019 |
Sep. 30, 2019 |
| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] |
|
|
| Unearned revenue |
$ 8,663
|
$ 9,610
|
| Long-term portion of unearned revenue |
1,716
|
$ 1,842
|
| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-01-01 |
|
|
| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] |
|
|
| Remaining performance obligation |
3,700
|
|
| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-04-01 |
|
|
| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] |
|
|
| Remaining performance obligation |
8,700
|
|
| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01 |
|
|
| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] |
|
|
| Remaining performance obligation |
$ 1,700
|
|