Borrowings and Financing Activities - Schedule of Debt (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Debt Instrument [Line Items]
Total FHLB advances	$ 153,550	$ 150,983
Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate
Debt Instrument [Line Items]
FHLB, floating SOFR advances	13,400
Senior notes
Debt Instrument [Line Items]
Total senior notes	1,412,473	1,409,473
Senior notes \| Senior Notes due 2024
Debt Instrument [Line Items]
Total senior notes	447,506	446,631
Senior notes \| Senior Notes due 2025
Debt Instrument [Line Items]
Total senior notes	519,817	518,405
Senior notes \| Senior Notes due 2027
Debt Instrument [Line Items]
Total senior notes	445,150	444,437
FHLB advances
Debt Instrument [Line Items]
2022	51,765	71,050
2023	52,994	52,995
2024	32,371	13,954
2025	9,984	9,984
2027	6,436	3,000
Total FHLB advances	$ 153,550	$ 150,983

Amount of borrowings as of the balance sheet date from the Federal Home Loan Bank, which are primarily used to cover shortages in the required reserve balance and liquidity shortages.

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