Inventory	6 Months Ended
Mar. 31, 2018
Inventory Disclosure [Abstract]
Inventory	Inventory Our inventory is comprised solely of finished goods. We record provisions to write down excess and obsolete( E&O ) inventory to estimated realizable value. We continually assess and refine our methodology for evaluating E&O inventory based on current facts and circumstances. Our methodology utilizes factors such as historical demand and subjective judgments and estimates to project future demand of our products. As such, the provisions we record to write down E&O inventory may fluctuate significantly in future periods. During the three months ended March 31, 2018 and 2017, charges to cost of sales related to provisions for E&O inventory and related items were $0.4 million and $3.1 million, respectively. During the six months ended March 31, 2018 and 2017, charges to cost of sales related to provisions for E&O inventory and related items were $4.8 million and $5.3 million, respectively. We believe that these amounts appropriately write-down E&O inventory to its net realizable value.

Inventory

Our inventory is comprised solely of finished goods. We record provisions to write down excess and obsolete( E&O ) inventory to estimated realizable value.

We continually assess and refine our methodology for evaluating E&O inventory based on current facts and circumstances. Our methodology utilizes factors such as historical demand and subjective judgments and estimates to project future demand of our products. As such, the provisions we record to write down E&O inventory may fluctuate significantly in future periods.

During the three months ended March 31, 2018 and 2017, charges to cost of sales related to provisions for E&O inventory and related items were $0.4 million and $3.1 million, respectively. During the six months ended March 31, 2018 and 2017, charges to cost of sales related to provisions for E&O inventory and related items were $4.8 million and $5.3 million, respectively. We believe that these amounts appropriately write-down E&O inventory to its net realizable value.