Fair Value - Level 3 Input Roll Forward, Recurring Basis (Details) - Recurring basis - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Roll forward of assets measured using Level 3 inputs on a recurring basis
Balance at the beginning of the period	$ 6,933,979	$ 5,785,871	$ 6,325,237	$ 5,329,147
Purchases and issuances, net	728,013	303,342	1,910,535	3,344,357
Capitalization of interest and advances	10,770	6,361	31,608	54,080
Sales and repayments	(202,965)	(71,078)	(472,344)	(1,335,966)
Mortgage servicing rights resulting from loan sales	450,936	345,077	1,299,992	1,359,632
Changes in fair value included in income arising from:
Changes in instrument specific credit risk	15,520	(9,217)	36,014	(39,427)
Other factors	186,982	(37,348)	(54,294)	(300,615)
Total changes in fair value included in income	202,502	(46,565)	(18,280)	(340,042)
Transfers from Level 3 to Level 2	(496,019)	(340,903)	(1,272,912)	(2,430,869)
Transfers to real estate acquired in settlement of loans	(144)		(450)	(386)
Transfers to loans held for sale	(24,692)	(32,000)	(201,006)	(29,848)
Exchange of mortgage servicing spread for interest only stripped securities	(98,066)		(98,066)
Balance at the end of the period	7,504,314	5,950,105	7,504,314	5,950,105
Changes in fair value recognized during the period relating to assets still held at the end of the period	248,267	22,919	(39,647)	332,032
Excess servicing spread financing
Roll forward of liabilities measured using Level 3 inputs on a recurring basis
Balance at the beginning of the period	1,940
Changes in fair value included in income	(122)
Balance at the end of the period	1,818		1,818
Changes in fair value recognized during the period relating to liability still outstanding at the end of the period	(122)
Mortgage servicing liabilities
Roll forward of liabilities measured using Level 3 inputs on a recurring basis
Balance at the beginning of the period		2,337	2,096	2,816
Changes in fair value included in income		(123)	(278)	(602)
Balance at the end of the period	1,818	2,214	1,818	2,214
Changes in fair value recognized during the period relating to liability still outstanding at the end of the period		(123)	(278)	(602)
Mortgage loans held for sale
Roll forward of assets measured using Level 3 inputs on a recurring basis
Balance at the beginning of the period	392,758	503,553	345,772	1,128,876
Purchases and issuances, net	681,022	260,721	1,733,158	2,994,447
Capitalization of interest and advances	10,770	6,361	31,608	54,080
Sales and repayments	(202,892)	(71,078)	(472,039)	(1,335,966)
Changes in fair value included in income arising from:
Changes in instrument specific credit risk	15,520	(9,217)	36,014	(39,427)
Other factors	(1,831)	(4,801)	(1,967)	(26,119)
Total changes in fair value included in income	13,689	(14,018)	34,047	(65,546)
Transfers from Level 3 to Level 2	(496,019)	(340,903)	(1,272,912)	(2,430,869)
Transfers to real estate acquired in settlement of loans	(144)		(450)	(386)
Balance at the end of the period	399,184	344,636	399,184	344,636
Changes in fair value recognized during the period relating to assets still held at the end of the period	6,519	(16,166)	10,465	(31,587)
Interest rate lock commitments
Roll forward of assets measured using Level 3 inputs on a recurring basis
Balance at the beginning of the period	30,636	65,151	25,844	322,193
Purchases and issuances, net	46,991	38,481	177,377	345,770
Changes in fair value included in income arising from:
Other factors	(32,161)	(127,835)	18,559	(694,318)
Total changes in fair value included in income	(32,161)	(127,835)	18,559	(694,318)
Transfers to loans held for sale	(24,692)	(32,000)	(201,006)	(29,848)
Balance at the end of the period	20,774	(56,203)	20,774	(56,203)
Changes in fair value recognized during the period relating to assets still held at the end of the period	20,774	(56,203)	20,774	(56,203)
Mortgage servicing rights
Roll forward of assets measured using Level 3 inputs on a recurring basis
Balance at the beginning of the period	6,510,585	5,217,167	5,953,621	3,878,078
Purchases and issuances, net		4,140		4,140
Sales and repayments	(73)		(305)
Mortgage servicing rights resulting from loan sales	450,936	345,077	1,299,992	1,359,632
Changes in fair value included in income arising from:
Other factors	220,974	95,288	(70,886)	419,822
Total changes in fair value included in income	220,974	95,288	(70,886)	419,822
Exchange of mortgage servicing spread for interest only stripped securities	(98,066)		(98,066)
Balance at the end of the period	7,084,356	5,661,672	7,084,356	5,661,672
Changes in fair value recognized during the period relating to assets still held at the end of the period	$ 220,974	$ 95,288	$ (70,886)	$ 419,822