Commitments and Contingencies (Unconditional Purchase Obligations - Narrative) (Details) $ in Billions |
Jun. 30, 2020
USD ($)
|
---|---|
Unrecorded Unconditional Purchase Obligation [Line Items] | |
Unconditional purchase obligation | $ 10.2 |
Helium Purchases | |
Unrecorded Unconditional Purchase Obligation [Line Items] | |
Unconditional purchase obligation | $ 8.6 |