Fair Value - Level 3 Input Roll Forward, Recurring Basis (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Roll forward of liabilities measured using Level 3 inputs on a recurring basis
Mortgage servicing liabilities resulting from loan sales				$ 98,147
Changes in fair value included in income				(1,037)
Recurring basis
Roll forward of assets measured using Level 3 inputs on a recurring basis
Balance at the beginning of the period	$ 5,785,871	$ 7,574,519	$ 5,329,147	7,933,369
Purchases and issuances, net	303,342	6,023,600	3,344,357	17,910,002
Capitalization of interest and advances	6,361	40,035	54,080	118,879
Sales and repayments	(71,078)	(4,286,574)	(1,335,966)	(9,081,815)
Mortgage servicing rights resulting from loan sales	345,077	432,429	1,359,632	1,386,324
Changes in fair value included in income arising from:
Changes in instrument specific credit risk	(9,217)	38,698	(39,427)	266,644
Other factors	(37,348)	2,359	(300,615)	32,760
Total changes in fair value included in income	(46,565)	41,057	(340,042)	299,404
Transfers from mortgage loans held for sale from Level 3 to Level 2	(340,903)	(3,068,841)	(2,430,869)	(10,493,751)
Transfers to real estate acquired in settlement of loans			(386)	(82)
Transfers from interest rate lock commitments to loans held for sale	(32,000)	(668,837)	(29,848)	(1,984,942)
Balance at the end of the period	5,950,105	6,087,388	5,950,105	6,087,388
Changes in fair value recognized during the period relating to assets still held at the end of the period	22,919	143,381	332,032	84,074
Roll forward of liabilities measured using Level 3 inputs on a recurring basis
Balance at the beginning of the period				177,074
Issuances				557
Accrual of interest on excess servicing spread financing				1,280
Repayment				(134,624)
Mortgage servicing liabilities resulting from loan sales				98,147
Changes in fair value included in income				(94,867)
Balance at the end of the period		47,567		47,567
Changes in fair value recognized during the period relating to liability still outstanding at the end of the period				(95,904)
Recurring basis | Excess servicing spread financing
Roll forward of liabilities measured using Level 3 inputs on a recurring basis
Balance at the beginning of the period	2,337			131,750
Issuances				557
Accrual of interest on excess servicing spread financing				1,280
Repayment				(134,624)
Changes in fair value included in income	(123)			1,037
Balance at the end of the period	2,214		2,214
Changes in fair value recognized during the period relating to liability still outstanding at the end of the period	(123)
Recurring basis | Mortgage servicing liabilities
Roll forward of assets measured using Level 3 inputs on a recurring basis
Mortgage servicing rights resulting from change in method of accounting		33,764
Roll forward of liabilities measured using Level 3 inputs on a recurring basis
Balance at the beginning of the period		100,091	2,816	45,324
Mortgage servicing liabilities resulting from loan sales				98,147
Changes in fair value included in income		(86,288)	(602)	(95,904)
Balance at the end of the period	2,214	47,567	2,214	47,567
Changes in fair value recognized during the period relating to liability still outstanding at the end of the period		(86,288)	(602)	(95,904)
Recurring basis | 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	503,553	3,818,261	1,128,876	4,675,169
Purchases and issuances, net	260,721	5,573,766	2,994,447	16,630,301
Capitalization of interest and advances	6,361	40,035	54,080	118,879
Sales and repayments	(71,078)	(4,286,574)	(1,335,966)	(9,081,815)
Changes in fair value included in income arising from:
Changes in instrument specific credit risk	(9,217)	38,698	(39,427)	266,644
Other factors	(4,801)		(26,119)
Total changes in fair value included in income	(14,018)	38,698	(65,546)	266,644
Transfers from mortgage loans held for sale from Level 3 to Level 2	(340,903)	(3,068,841)	(2,430,869)	(10,493,751)
Transfers to real estate acquired in settlement of loans			(386)	(82)
Balance at the end of the period	344,636	2,115,345	344,636	2,115,345
Changes in fair value recognized during the period relating to assets still held at the end of the period	(16,166)	16,415	(31,587)	79,529
Recurring basis | Interest rate lock commitments
Roll forward of assets measured using Level 3 inputs on a recurring basis
Balance at the beginning of the period	65,151	343,610	322,193	677,026
Purchases and issuances, net	38,481	449,834	345,770	1,279,701
Changes in fair value included in income arising from:
Other factors	(127,835)	236,316	(694,318)	389,138
Total changes in fair value included in income	(127,835)	236,316	(694,318)	389,138
Transfers from interest rate lock commitments to loans held for sale	(32,000)	(668,837)	(29,848)	(1,984,942)
Balance at the end of the period	(56,203)	360,923	(56,203)	360,923
Changes in fair value recognized during the period relating to assets still held at the end of the period	(56,203)	360,923	(56,203)	360,923
Recurring basis | Mortgage servicing rights
Roll forward of assets measured using Level 3 inputs on a recurring basis
Balance at the beginning of the period	5,217,167	3,412,648	3,878,078	2,581,174
Purchases and issuances, net	4,140		4,140
Mortgage servicing rights resulting from loan sales	345,077	432,429	1,359,632	1,386,324
Changes in fair value included in income arising from:
Other factors	95,288	(233,957)	419,822	(356,378)
Total changes in fair value included in income	95,288	(233,957)	419,822	(356,378)
Balance at the end of the period	5,661,672	3,611,120	5,661,672	3,611,120
Changes in fair value recognized during the period relating to assets still held at the end of the period	$ 95,288	$ (233,957)	$ 419,822	$ (356,378)