XML 51 R40.htm IDEA: XBRL DOCUMENT v3.22.2.2
Investments - Summary of Investments by Type of Security (Details) - USD ($)
$ in Thousands
Jun. 30, 2022
Sep. 30, 2021
Schedule Of Available For Sale Securities [Line Items]    
Cost $ 70,437 $ 197,165
Gross Unrealized Gains 0 12
Gross Unrealized Losses (1,372) (69)
Short-term investments: 49,531 149,057
Long-term investments: 19,534 48,051
Fair Market Value 69,065 197,108
U.S. Treasury    
Schedule Of Available For Sale Securities [Line Items]    
Amortized cost, short-term 4,024 4,222
Amortized cost, long-term 5,440 6,996
Gross Unrealized Gains, short-term 0 1
Gross Unrealized Gains, long-term 0 1
Gross Unrealized Losses, short-term (71) 0
Gross Unrealized Losses, long-term (212) (2)
Short-term investments: 3,953 4,223
Long-term investments: 5,228 6,995
Asset-backed securities    
Schedule Of Available For Sale Securities [Line Items]    
Amortized cost, short-term   4,812
Gross Unrealized Gains, short-term   1
Gross Unrealized Losses, short-term   (2)
Short-term investments:   4,811
Corporate debt securities    
Schedule Of Available For Sale Securities [Line Items]    
Amortized cost, short-term 43,346 140,042
Amortized cost, long-term 14,750 38,184
Gross Unrealized Gains, short-term 0 6
Gross Unrealized Gains, long-term 0 3
Gross Unrealized Losses, short-term (600) (25)
Gross Unrealized Losses, long-term (444) (39)
Short-term investments: 42,746 140,023
Long-term investments: 14,306 38,148
Foreign government and agency securities    
Schedule Of Available For Sale Securities [Line Items]    
Amortized cost, short-term 2,877  
Amortized cost, long-term   2,909
Gross Unrealized Gains, short-term 0  
Gross Unrealized Gains, long-term   0
Gross Unrealized Losses, short-term (45)  
Gross Unrealized Losses, long-term   (1)
Short-term investments: $ 2,832  
Long-term investments:   $ 2,908