Commitments and Contingencies (Details) $ in Millions |
12 Months Ended | ||
---|---|---|---|
Sep. 30, 2019
USD ($)
Bcf
|
Sep. 30, 2018
USD ($)
|
Sep. 30, 2017
USD ($)
|
|
Long Term Purchase Commitment [Line Items] | |||
Self-insured retention | $ | $ 1.0 | ||
Purchases under contract | $ | $ 50.8 | $ 57.2 | $ 49.7 |
Supply Commitment | |||
Long Term Purchase Commitment [Line Items] | |||
Contract term | 1 year | ||
Supply Commitment | Short-term Contract with Customer | |||
Long Term Purchase Commitment [Line Items] | |||
Contract term | 1 year | ||
Purchase commitment volume | Bcf | 40,100 | ||
Supply Commitment | Long-term Contract with Customer Within Two To Three Years | |||
Long Term Purchase Commitment [Line Items] | |||
Purchase commitment volume | Bcf | 1,600 | ||
Minimum | Supply Commitment | Long-term Contract with Customer Within Two To Three Years | |||
Long Term Purchase Commitment [Line Items] | |||
Contract term | 2 years | ||
Maximum | Supply Commitment | Long-term Contract with Customer Within Two To Three Years | |||
Long Term Purchase Commitment [Line Items] | |||
Contract term | 3 years |