Segment and Related Information (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2020 USD ($) segment	Mar. 31, 2019 USD ($)	Dec. 31, 2019 USD ($)
Information about the revenues, operating results, goodwill and assets
Number of reportable segments | segment	4
Net interest income (expense)	$ 110,336	$ 108,289
Provision (reversal of) for credit losses	34,549	951
Noninterest income	271,713	215,963
Noninterest expense	281,901	278,747
Income from continuing operations before income taxes	65,599	44,554
Income before taxes from discontinued operations	4,014	6,809
Income before income taxes	69,613	51,363
Goodwill	267,447		$ 267,447
Assets held for sale	249,758		248,429
Total assets	15,706,250		15,172,448
Operating segment | Banking
Information about the revenues, operating results, goodwill and assets
Net interest income (expense)	93,923	92,690
Provision (reversal of) for credit losses	34,275	1,025
Noninterest income	8,771	10,621
Noninterest expense	56,967	60,726
Income from continuing operations before income taxes	11,452	41,560
Income before income taxes	11,452	41,560
Goodwill	247,368		247,368
Total assets	11,616,994		11,147,344
Operating segment | Broker-Dealer
Information about the revenues, operating results, goodwill and assets
Net interest income (expense)	13,173	12,850
Provision (reversal of) for credit losses	274	(74)
Noninterest income	86,209	91,307
Noninterest expense	80,939	87,807
Income from continuing operations before income taxes	18,169	16,424
Income before income taxes	18,169	16,424
Goodwill	7,008		7,008
Total assets	3,406,300		3,457,068
Operating segment | Mortgage Origination Segment
Information about the revenues, operating results, goodwill and assets
Net interest income (expense)	368	(467)
Noninterest income	178,968	118,033
Noninterest expense	139,552	114,677
Income from continuing operations before income taxes	39,784	2,889
Income before income taxes	39,784	2,889
Goodwill	13,071		13,071
Total assets	2,607,131		2,357,415
Operating segment | Insurance Segment
Information about the revenues, operating results, goodwill and assets
Income before taxes from discontinued operations	4,014	6,809
Income before income taxes	4,014	6,809
Assets held for sale	249,758		248,429
Total assets	249,758		248,429
Corporate
Information about the revenues, operating results, goodwill and assets
Net interest income (expense)	(1,656)	(1,330)
Noninterest income	2,309	538
Noninterest expense	4,853	15,562
Income from continuing operations before income taxes	(4,200)	(16,354)
Income before income taxes	(4,200)	(16,354)
Total assets	2,448,412		2,393,604
All Other and Eliminations.
Information about the revenues, operating results, goodwill and assets
Net interest income (expense)	4,528	4,546
Noninterest income	(4,544)	(4,536)
Noninterest expense	(410)	(25)
Income from continuing operations before income taxes	394	35
Income before income taxes	394	$ 35
Total assets	$ (4,622,345)		$ (4,431,412)