Fair Value - Level 3 Unobservable Inputs, Mortgage Loans and IRLC (Details) $ in Thousands	Dec. 31, 2021 USD ($) item	Dec. 31, 2020 USD ($) item
Excess servicing spread financing
Loans held for sale | $	$ 9,742,483	$ 11,616,400
Mortgage loans held for sale
Excess servicing spread financing
Loans held for sale | $	9,742,483	11,616,400
Mortgage loans held for sale | Level 3
Excess servicing spread financing
Loans held for sale | $	$ 1,128,876	$ 4,675,169
Mortgage loans held for sale | Discount rate | Level 3 | Minimum
Excess servicing spread financing
Input	2.2	2.8
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	2.3	2.8
Mortgage loans held for sale | Twelve-month projected housing price index Change | Level 3 | Minimum
Excess servicing spread financing
Input	6.1	2.7
Mortgage loans held for sale | Twelve-month projected housing price index Change | Level 3 | Maximum
Excess servicing spread financing
Input	6.5	3.5
Mortgage loans held for sale | Twelve-month projected housing price index Change | Level 3 | Weighted average
Excess servicing spread financing
Input	6.2	3.0
Mortgage loans held for sale | Prepayment/resale speed | Level 3 | Minimum
Excess servicing spread financing
Input	0.4	0.4
Mortgage loans held for sale | Prepayment/resale speed | Level 3 | Maximum
Excess servicing spread financing
Input	30.3	31.3
Mortgage loans held for sale | Prepayment/resale speed | Level 3 | Weighted average
Excess servicing spread financing
Input	22.0	21.9
Mortgage loans held for sale | Total prepayment speed | Level 3 | Minimum
Excess servicing spread financing
Input	0.4	0.5
Mortgage loans held for sale | Total prepayment speed | Level 3 | Maximum
Excess servicing spread financing
Input	39.3	42.9
Mortgage loans held for sale | Total prepayment speed | Level 3 | Weighted average
Excess servicing spread financing
Input	28.2	29.2
Interest rate lock commitments | Level 3
Excess servicing spread financing
Interest rate lock commitment | $	$ 322,193	$ 677,026
Interest rate lock commitments | Pull-through rate | Level 3 | Minimum
Excess servicing spread financing
Input	8.0	10.1
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	78.4	82.7
Interest rate lock commitments | Mortgage servicing rights value expressed as servicing fee multiple | Level 3 | Minimum
Excess servicing spread financing
Input	(8.5)	0.7
Interest rate lock commitments | Mortgage servicing rights value expressed as servicing fee multiple | Level 3 | Maximum
Excess servicing spread financing
Input	6.7	5.3
Interest rate lock commitments | Mortgage servicing rights value expressed as servicing fee multiple | Level 3 | Weighted average
Excess servicing spread financing
Input	3.8	3.6
Interest rate lock commitments | Percentage of unpaid principal balance | Level 3 | Minimum
Excess servicing spread financing
Input	(1.6)	0.1
Interest rate lock commitments | Percentage of unpaid principal balance | Level 3 | Maximum
Excess servicing spread financing
Input	3.6	2.6
Interest rate lock commitments | Percentage of unpaid principal balance | Level 3 | Weighted average
Excess servicing spread financing
Input	1.5	1.2