Fair Value - Level 3 Unobservable Inputs, Mortgage Loans and IRLC (Details) $ in Thousands	Mar. 31, 2022 USD ($) item	Dec. 31, 2021 USD ($) item
Excess servicing spread financing
Loans held for sale | $	$ 5,119,234	$ 9,742,483
Level 3
Excess servicing spread financing
Loans held for sale | $	$ 776,590	$ 1,128,876
Mortgage loans held for sale | Discount rate | Level 3 | Minimum
Excess servicing spread financing
Input	2.2	2.2
Mortgage loans held for sale | Discount rate | Level 3 | Maximum
Excess servicing spread financing
Input	9.2	9.2
Mortgage loans held for sale | Discount rate | Level 3 | Weighted average
Excess servicing spread financing
Input	2.4	2.3
Mortgage loans held for sale | Twelve-month projected housing price index Change | Level 3 | Minimum
Excess servicing spread financing
Input	5.9	6.1
Mortgage loans held for sale | Twelve-month projected housing price index Change | Level 3 | Maximum
Excess servicing spread financing
Input	6.4	6.5
Mortgage loans held for sale | Twelve-month projected housing price index Change | Level 3 | Weighted average
Excess servicing spread financing
Input	6.0	6.2
Mortgage loans held for sale | Prepayment/resale speed | Level 3 | Minimum
Excess servicing spread financing
Input	0.3	0.4
Mortgage loans held for sale | Prepayment/resale speed | Level 3 | Maximum
Excess servicing spread financing
Input	31.6	30.3
Mortgage loans held for sale | Prepayment/resale speed | Level 3 | Weighted average
Excess servicing spread financing
Input	24.7	22.0
Mortgage loans held for sale | Total prepayment speed | Level 3 | Minimum
Excess servicing spread financing
Input	0.3	0.4
Mortgage loans held for sale | Total prepayment speed | Level 3 | Maximum
Excess servicing spread financing
Input	41.0	39.3
Mortgage loans held for sale | Total prepayment speed | Level 3 | Weighted average
Excess servicing spread financing
Input	31.3	28.2
Interest rate lock commitments | Level 3
Excess servicing spread financing
Loans held for sale | $	$ 37,899	$ 322,193
Interest rate lock commitments | Pull-through rate | Level 3 | Minimum
Excess servicing spread financing
Input	8.0	8.0
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	81.4	78.4
Interest rate lock commitments | Mortgage servicing rights value expressed as servicing fee multiple | Level 3 | Minimum
Excess servicing spread financing
Input	(5.5)	(8.5)
Interest rate lock commitments | Mortgage servicing rights value expressed as servicing fee multiple | Level 3 | Maximum
Excess servicing spread financing
Input	6.8	6.7
Interest rate lock commitments | Mortgage servicing rights value expressed as servicing fee multiple | Level 3 | Weighted average
Excess servicing spread financing
Input	4.3	3.8
Interest rate lock commitments | Percentage of unpaid principal balance | Level 3 | Minimum
Excess servicing spread financing
Input	(1.1)	(1.6)
Interest rate lock commitments | Percentage of unpaid principal balance | Level 3 | Maximum
Excess servicing spread financing
Input	3.9	3.6
Interest rate lock commitments | Percentage of unpaid principal balance | Level 3 | Weighted average
Excess servicing spread financing
Input	1.8	1.5