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v3.22.1

Fair Value Measurements - Investments by Contractual Maturity Date (Details) - USD ($) $ in Thousands | Mar. 31, 2022 | Sep. 30, 2021
--- | --- | ---
Amortized Cost, Available-for-sale securities |  |
Amortized Cost | $ 1,921,988 | $ 2,090,070
Gross Unrealized Gains / Losses, Available-for-sale securities |  |
Gross unrealized gains | 10,988 | 50,829
Gross unrealized loss | (23,371) | (2,640)
Fair Value, Available-for-sale securities |  |
Fair value | $ 1,909,605 | $ 2,138,259
Yield, Available-for-sale securities |  |
Yield | 1.95% | 1.69%
Amortized Cost, Held-to-maturity securities |  |
Held-to-maturity securities, amortized cost | $ 301,221 | $ 366,025
Gross Unrealized Gains / Losses, Held-to-maturity securities |  |
Held-to-maturity securities, gross unrealized gains | 170 | 13,522
Held-to-maturity securities, gross unrealized losses | (7,037) | 0
Fair Value, Held-to-maturity securities |  |
Held-to-maturity securities, fair value | $ 294,354 | $ 379,547
Yield, Held-to-maturity securities |  |
Held-to-maturity securities, yield | 3.16% | 3.17%
Investments | $ 2,223,209 | $ 2,456,095
Gross unrealized gains on investments | 11,158 | 64,351
Gross unrealized losses on investments | (30,408) | (2,640)
Total financial assets | $ 2,203,959 | $ 2,517,806
Yield on investments | 2.11% | 1.89%
U.S. government and agency securities |  |
Amortized Cost, Available-for-sale securities |  |
Amortized cost, 1 to 5 years | $ 50,441 | $ 47,339
Amortized cost, 5 to 10 years |  | 14,064
Gross Unrealized Gains / Losses, Available-for-sale securities |  |
Gross unrealized gains, 1 to 5 years | 27 | 240
Gross unrealized gains, 5 to 10 years |  | 136
Gross unrealized losses, 1 to 5 years | (659) | 0
Gross unrealized losses, 5 to 10 years |  | 0
Fair Value, Available-for-sale securities |  |
Fair value, 1 to 5 years | $ 49,809 | 47,579
Fair value, 5 to 10 years |  | $ 14,200
Yield, Available-for-sale securities |  |
Yield, 1 to 5 years | 1.07% | 0.44%
Yield, 5 to 10 years |  | 2.05%
Asset-backed securities |  |
Amortized Cost, Available-for-sale securities |  |
Amortized cost, 1 to 5 years | $ 18,908 | $ 19,730
Amortized cost, 5 to 10 years | 62,883 | 71,207
Amortized cost, over 10 years | 807,611 | 973,892
Gross Unrealized Gains / Losses, Available-for-sale securities |  |
Gross unrealized gains, 1 to 5 years | 0 | 0
Gross unrealized gains, 5 to 10 years | 121 | 412
Gross unrealized gains, over 10 years | 2,144 | 14,069
Gross unrealized losses, 1 to 5 years | (602) | (434)
Gross unrealized losses, 5 to 10 years | (202) | (97)
Gross unrealized losses, over 10 years | (1,437) | (98)
Fair Value, Available-for-sale securities |  |
Fair value, 1 to 5 years | 18,306 | 19,296
Fair value, 5 to 10 years | 62,802 | 71,522
Fair value, over 10 years | $ 808,318 | $ 987,863
Yield, Available-for-sale securities |  |
Yield, 1 to 5 years | 1.08% | 0.52%
Yield, 5 to 10 years | 0.79% | 0.57%
Yield, over 10 years | 1.28% | 0.94%
Corporate debt securities |  |
Amortized Cost, Available-for-sale securities |  |
Amortized cost, within 1 year |  | $ 225,928
Amortized cost, 1 to 5 years | $ 226,170 | 86,802
Amortized cost, 5 to 10 years | 115,010 | 28,804
Gross Unrealized Gains / Losses, Available-for-sale securities |  |
Gross unrealized gains, within 1 year |  | 7,860
Gross unrealized gains, 1 to 5 years | 2,301 | 1,345
Gross unrealized gains, 5 to 10 years | 0 | 249
Gross unrealized losses, Within 1 year |  | 0
Gross unrealized losses, 1 to 5 years | 0 | 0
Gross unrealized losses, 5 to 10 years | (9,482) | 0
Fair Value, Available-for-sale securities |  |
Fair value, within 1 year |  | 233,788
Fair value, 1 to 5 years | 228,471 | 88,147
Fair value, 5 to 10 years | $ 105,528 | $ 29,053
Yield, Available-for-sale securities |  |
Yield, within 1 year |  | 1.57%
Yield, 1 to 5 years | 1.79% | 4.64%
Yield, 5 to 10 years | 3.87% | 1.95%
Municipal bonds due |  |
Amortized Cost, Available-for-sale securities |  |
Amortized cost, within 1 year | $ 1,509 | $ 1,493
Amortized cost, 5 to 10 years | 5,766 | 5,781
Amortized cost, over 10 years | 29,890 | 29,909
Gross Unrealized Gains / Losses, Available-for-sale securities |  |
Gross unrealized gains, within 1 year | 3 | 17
Gross unrealized gains, 5 to 10 years | 0 | 294
Gross unrealized gains, over 10 years | 1,456 | 2,490
Gross unrealized losses, Within 1 year | 0 | 0
Gross unrealized losses, 5 to 10 years | (156) | 0
Gross unrealized losses, over 10 years | 0 | 0
Fair Value, Available-for-sale securities |  |
Fair value, within 1 year | 1,512 | 1,510
Fair value, 5 to 10 years | 5,610 | 6,075
Fair value, over 10 years | $ 31,346 | $ 32,399
Yield, Available-for-sale securities |  |
Yield, within 1 year | 0.00% | 0.00%
Yield, 5 to 10 years | 0.16% | 0.22%
Yield, over 10 years | 5.85% | 5.85%
Agency pass-through certificates |  |
Amortized Cost, Available-for-sale securities |  |
Amortized cost, without single maturity date | $ 603,800 | $ 585,121
Gross Unrealized Gains / Losses, Available-for-sale securities |  |
Gross unrealized gains, without single maturity date | 4,936 | 23,717
Gross unrealized losses, without single maturity date | (10,833) | (2,011)
Fair Value, Available-for-sale securities |  |
Fair value, without single maturity date | $ 597,903 | $ 606,827
Yield, Available-for-sale securities |  |
Yield, without single maturity date | 2.60% | 2.60%
Amortized Cost, Held-to-maturity securities |  |
Held-to-maturity securities, amortized cost | $ 301,221 | $ 366,025
Gross Unrealized Gains / Losses, Held-to-maturity securities |  |
Held-to-maturity securities, gross unrealized gains | 170 | 13,522
Held-to-maturity securities, gross unrealized losses | (7,037) | 0
Fair Value, Held-to-maturity securities |  |
Held-to-maturity securities, fair value | $ 294,354 | $ 379,547
Yield, Held-to-maturity securities |  |
Held-to-maturity securities, yield | 3.16% | 3.17%

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