Condensed Consolidated Statements of Cash Flows - USD ($)	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Operating activities:
Net income	$ 104,077,000	$ 113,400,000
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	1,204,000	1,061,000
Provision for credit losses	8,663,000	1,348,000
Gain on sale of loans	(39,529,000)	(53,742,000)
Proceeds from sales of loans	14,491,319,000	30,088,479,000
Loans and participations originated and purchased for sale	(13,918,978,000)	(29,764,386,000)
Purchases of low-income housing tax credits for sale	(9,829,000)
Change in mortgage servicing rights for paydowns and fair value adjustments	(9,367,000)	543,000
Net change in:
Mortgage loans in process of securitization	246,193,000	(123,181,000)
Other assets and receivables	(17,738,000)	(4,072,000)
Other liabilities	18,389,000	12,071,000
Other	371,000	(906,000)
Net cash provided by operating activities	874,775,000	270,615,000
Investing activities:
Net change in securities purchased under agreements to resell	2,368,000	73,000
Purchases of available for sale securities	(47,866,000)	(130,204,000)
Proceeds from the sale of available for sale securities	0	34,469,000
Proceeds from calls, maturities and paydowns of available for sale securities	12,206,000	49,444,000
Purchases of loans	(92,533,000)	(250,678,000)
Net change in loans receivable	(1,199,040,000)	(126,810,000)
Proceeds from sale of loans receivable		262,086,000
Purchase of FHLB stock	(10,326,000)	(111,000)
Proceeds from sale of FHLB stock	784,000
Proceeds from sale of servicing rights		438,000
Purchases of premises and equipment	(5,113,000)	(2,686,000)
Purchase of servicing rights	(2,057,000)
Purchase of limited partnership interests	(13,225,000)	(1,603,000)
Cash paid in deconsolidation of subsidiary		(464,000)
Other investing activities	2,924,000	366,000
Net cash used in investing activities	(1,351,878,000)	(165,680,000)
Financing activities:
Net change in deposits	(682,875,000)	629,407,000
Proceeds from borrowings	21,595,000,000	20,406,224,000
Repayment of borrowings	(21,190,050,000)	(21,053,107,000)
Proceeds from notes payable	2,000,000
Proceeds from issuance of preferred stock		191,084,000
Repurchase of preferred stock		(41,625,000)
Repurchase of common stock	(3,935,000)
Dividends	(17,505,000)	(14,597,000)
Net cash provided by (used in) financing activities	(297,365,000)	117,386,000
Net Change in Cash and Cash Equivalents	(774,468,000)	222,321,000
Cash and Cash Equivalents, Beginning of Period	1,032,614,000	179,728,000
Cash and Cash Equivalents, End of Period	258,146,000	402,049,000
Supplemental Cash Flows Information:
Interest paid	25,191,000	14,622,000
Income taxes paid, net of refunds	28,331,000	41,667,000
Transfer of loans from loans receivable to loans held for sale		166,688,000
Deconsolidation of debt fund entities