Fair Value of Assets and Liabilities - Fair Value Measurements on a Recurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Recurring measurements
Financial Assets
Loans held for sale, at fair value	$ 60,797	$ 166,572
Total assets measured at fair value on a recurring basis	9,235,588	5,513,192
Financial Liabilities
Total financial liabilities	80	2,056
Interest rate caps \| Recurring measurements
Financial Assets
Interest rate caps	934	201
Interest rate locks \| Recurring measurements
Financial Assets
Interest rate caps	3,008	8,605
TBA hedge
Financial Liabilities
TBA hedge
TBA hedge \| Recurring measurements
Financial Liabilities
TBA hedge	80	2,056
U.S. government and federal agency \| Recurring measurements
Financial Assets
Debt securities, available-for-sale	1,346,749	38,588
U.S. government sponsored enterprises \| Recurring measurements
Financial Assets
Debt securities, available-for-sale	240,693	9,781
State and local governments \| Recurring measurements
Financial Assets
Debt securities, available-for-sale	488,858	1,416,683
Corporate bonds \| Recurring measurements
Financial Assets
Debt securities, available-for-sale	180,752	349,098
Residential mortgage-backed securities \| Recurring measurements
Financial Assets
Debt securities, available-for-sale	5,699,659	2,289,090
Commercial mortgage-backed securities \| Recurring measurements
Financial Assets
Debt securities, available-for-sale	1,214,138	1,234,574
Level 1 \| Recurring measurements
Financial Assets
Loans held for sale, at fair value	0	0
Total assets measured at fair value on a recurring basis	0	0
Financial Liabilities
Total financial liabilities	0	0
Level 1 \| Interest rate caps \| Recurring measurements
Financial Assets
Interest rate caps		0
Level 1 \| Interest rate locks \| Recurring measurements
Financial Assets
Interest rate caps	0	0
Level 1 \| TBA hedge \| Recurring measurements
Financial Liabilities
TBA hedge	0	0
Level 1 \| U.S. government and federal agency \| Recurring measurements
Financial Assets
Debt securities, available-for-sale	0	0
Level 1 \| U.S. government sponsored enterprises \| Recurring measurements
Financial Assets
Debt securities, available-for-sale	0	0
Level 1 \| State and local governments \| Recurring measurements
Financial Assets
Debt securities, available-for-sale	0	0
Level 1 \| Corporate bonds \| Recurring measurements
Financial Assets
Debt securities, available-for-sale	0	0
Level 1 \| Residential mortgage-backed securities \| Recurring measurements
Financial Assets
Debt securities, available-for-sale	0	0
Level 1 \| Commercial mortgage-backed securities \| Recurring measurements
Financial Assets
Debt securities, available-for-sale	0	0
Level 2 \| Recurring measurements
Financial Assets
Loans held for sale, at fair value	60,797	166,572
Total assets measured at fair value on a recurring basis	9,235,588	5,513,192
Financial Liabilities
Total financial liabilities	80	2,056
Level 2 \| Interest rate caps \| Recurring measurements
Financial Assets
Interest rate caps	934	201
Level 2 \| Interest rate locks \| Recurring measurements
Financial Assets
Interest rate caps	3,008	8,605
Level 2 \| TBA hedge \| Recurring measurements
Financial Liabilities
TBA hedge	80	2,056
Level 2 \| U.S. government and federal agency \| Recurring measurements
Financial Assets
Debt securities, available-for-sale	1,346,749	38,588
Level 2 \| U.S. government sponsored enterprises \| Recurring measurements
Financial Assets
Debt securities, available-for-sale	240,693	9,781
Level 2 \| State and local governments \| Recurring measurements
Financial Assets
Debt securities, available-for-sale	488,858	1,416,683
Level 2 \| Corporate bonds \| Recurring measurements
Financial Assets
Debt securities, available-for-sale	180,752	349,098
Level 2 \| Residential mortgage-backed securities \| Recurring measurements
Financial Assets
Debt securities, available-for-sale	5,699,659	2,289,090
Level 2 \| Commercial mortgage-backed securities \| Recurring measurements
Financial Assets
Debt securities, available-for-sale	1,214,138	1,234,574
Level 3 \| Recurring measurements
Financial Assets
Loans held for sale, at fair value	0	0
Total assets measured at fair value on a recurring basis	0	0
Financial Liabilities
Total financial liabilities	0	0
Level 3 \| Interest rate caps \| Recurring measurements
Financial Assets
Interest rate caps		0
Level 3 \| Interest rate locks \| Recurring measurements
Financial Assets
Interest rate caps	0	0
Level 3 \| TBA hedge \| Recurring measurements
Financial Liabilities
TBA hedge	0	0
Level 3 \| U.S. government and federal agency \| Recurring measurements
Financial Assets
Debt securities, available-for-sale	0	0
Level 3 \| U.S. government sponsored enterprises \| Recurring measurements
Financial Assets
Debt securities, available-for-sale	0	0
Level 3 \| State and local governments \| Recurring measurements
Financial Assets
Debt securities, available-for-sale	0	0
Level 3 \| Corporate bonds \| Recurring measurements
Financial Assets
Debt securities, available-for-sale	0	0
Level 3 \| Residential mortgage-backed securities \| Recurring measurements
Financial Assets
Debt securities, available-for-sale	0	0
Level 3 \| Commercial mortgage-backed securities \| Recurring measurements
Financial Assets
Debt securities, available-for-sale	$ 0	$ 0

Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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