Segment and Related Information (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022 USD ($)	Sep. 30, 2021 USD ($)	Sep. 30, 2022 USD ($) segment item	Sep. 30, 2021 USD ($)	Dec. 31, 2021 USD ($)
Information about the revenues, operating results, goodwill and assets
Number of primary business units | item			2
Number of reportable segments | segment			3
Net interest income (expense)	$ 123,486	$ 105,090	$ 335,533	$ 318,688
Provision for (reversal of) credit losses	(780)	(5,819)	4,671	(39,648)
Noninterest income	206,975	367,945	662,676	1,125,429
Noninterest expense	288,738	355,174	873,631	1,065,204
Income before income taxes	42,503	123,680	119,907	418,561
Goodwill	267,447		267,447		$ 267,447
Total assets	16,615,291		16,615,291		18,689,080
Operating Segments | Banking
Information about the revenues, operating results, goodwill and assets
Net interest income (expense)	110,939	99,978	304,269	309,330
Provision for (reversal of) credit losses	(650)	(5,775)	4,325	(39,725)
Noninterest income	12,200	11,727	37,438	33,293
Noninterest expense	60,160	54,567	175,921	167,869
Income before income taxes	63,629	62,913	161,461	214,479
Goodwill	247,368		247,368		247,368
Total assets	13,455,679		13,455,679		14,944,249
Operating Segments | Broker-Dealer
Information about the revenues, operating results, goodwill and assets
Net interest income (expense)	13,386	10,427	37,481	31,623
Provision for (reversal of) credit losses	(130)	(44)	346	77
Noninterest income	100,798	116,143	249,139	298,229
Noninterest expense	96,843	109,193	268,307	287,831
Income before income taxes	17,471	17,421	17,967	41,944
Goodwill	7,008		7,008		7,008
Total assets	2,866,990		2,866,990		3,673,346
Operating Segments | Mortgage Origination Segment
Information about the revenues, operating results, goodwill and assets
Net interest income (expense)	(2,939)	(3,503)	(6,066)	(16,554)
Noninterest income	98,200	242,270	381,477	794,679
Noninterest expense	118,345	176,587	386,372	573,884
Income before income taxes	(23,084)	62,180	(10,961)	204,241
Goodwill	13,071		13,071		13,071
Total assets	1,405,712		1,405,712		2,207,822
Operating Segments | Corporate
Information about the revenues, operating results, goodwill and assets
Net interest income (expense)	(3,276)	(4,341)	(9,856)	(13,720)
Noninterest income	1,809	757	5,655	8,140
Noninterest expense	14,034	15,355	44,388	37,015
Income before income taxes	(15,501)	(18,939)	(48,589)	(42,595)
Total assets	2,453,933		2,453,933		2,940,670
All Other and Eliminations
Information about the revenues, operating results, goodwill and assets
Net interest income (expense)	5,376	2,529	9,705	8,009
Noninterest income	(6,032)	(2,952)	(11,033)	(8,912)
Noninterest expense	(644)	(528)	(1,357)	(1,395)
Income before income taxes	(12)	$ 105	29	$ 492
Total assets	$ (3,567,023)		$ (3,567,023)		$ (5,077,007)