Fair Value - Level 3 Unobservable Inputs, Mortgage Loans and IRLC (Details) $ in Thousands	Sep. 30, 2023 USD ($) item	Dec. 31, 2022 USD ($) item
Excess servicing spread financing
Loans held for sale | $	$ 5,186,656	$ 3,509,300
Level 3
Excess servicing spread financing
Loans held for sale | $	$ 399,184	$ 345,772
Mortgage loans held for sale | Discount rate | Level 3 | Minimum
Excess servicing spread financing
Input	7.9	5.5
Mortgage loans held for sale | Discount rate | Level 3 | Maximum
Excess servicing spread financing
Input	10.2	10.2
Mortgage loans held for sale | Discount rate | Level 3 | Weighted average
Excess servicing spread financing
Input	7.9	5.7
Mortgage loans held for sale | Twelve-month projected housing price index Change | Level 3 | Minimum
Excess servicing spread financing
Input	0.2	(1.9)
Mortgage loans held for sale | Twelve-month projected housing price index Change | Level 3 | Maximum
Excess servicing spread financing
Input	0.3	(1.7)
Mortgage loans held for sale | Twelve-month projected housing price index Change | Level 3 | Weighted average
Excess servicing spread financing
Input	0.2	(1.8)
Mortgage loans held for sale | Prepayment/resale speed | Level 3 | Minimum
Excess servicing spread financing
Input	4.0	4.7
Mortgage loans held for sale | Prepayment/resale speed | Level 3 | Maximum
Excess servicing spread financing
Input	43.0	25.6
Mortgage loans held for sale | Prepayment/resale speed | Level 3 | Weighted average
Excess servicing spread financing
Input	28.0	21.6
Mortgage loans held for sale | Total prepayment speed | Level 3 | Minimum
Excess servicing spread financing
Input	4.1	4.8
Mortgage loans held for sale | Total prepayment speed | Level 3 | Maximum
Excess servicing spread financing
Input	55.4	36.1
Mortgage loans held for sale | Total prepayment speed | Level 3 | Weighted average
Excess servicing spread financing
Input	35.2	29.4
Interest rate lock commitments | Level 3
Excess servicing spread financing
Fair Value | $	$ 20,774	$ 25,844
Committed amount | $	$ 7,527,726	$ 7,009,119
Interest rate lock commitments | Pull-through rate | Level 3 | Minimum
Excess servicing spread financing
Input	14.7	10.3
Interest rate lock commitments | Pull-through rate | Level 3 | Maximum
Excess servicing spread financing
Input	100	100
Interest rate lock commitments | Pull-through rate | Level 3 | Weighted average
Excess servicing spread financing
Input	86.9	82.8
Interest rate lock commitments | Mortgage servicing rights value expressed as servicing fee multiple | Level 3 | Minimum
Excess servicing spread financing
Input	1.1	(1.3)
Interest rate lock commitments | Mortgage servicing rights value expressed as servicing fee multiple | Level 3 | Maximum
Excess servicing spread financing
Input	8.2	7.7
Interest rate lock commitments | Mortgage servicing rights value expressed as servicing fee multiple | Level 3 | Weighted average
Excess servicing spread financing
Input	5.0	4.3
Interest rate lock commitments | Percentage of unpaid principal balance | Level 3 | Minimum
Excess servicing spread financing
Input	0.3	(0.2)
Interest rate lock commitments | Percentage of unpaid principal balance | Level 3 | Maximum
Excess servicing spread financing
Input	4.5	3.8
Interest rate lock commitments | Percentage of unpaid principal balance | Level 3 | Weighted average
Excess servicing spread financing
Input	2.1	2.0