Segment and Related Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2015 segment	Mar. 31, 2014	Dec. 31, 2014
Segment and Related Information
Number of reportable segments	4us-gaap_NumberOfReportableSegments
Information about the revenues, operating results, goodwill and assets
Net interest income (expense)	$ 93,392us-gaap_InterestIncomeExpenseNet	$ 85,421us-gaap_InterestIncomeExpenseNet
Provision for loan losses	2,687us-gaap_ProvisionForLoanAndLeaseLosses	3,242us-gaap_ProvisionForLoanAndLeaseLosses
Noninterest income	354,372us-gaap_NoninterestIncome	170,100us-gaap_NoninterestIncome
Noninterest expense	314,476us-gaap_NoninterestExpense	212,629us-gaap_NoninterestExpense
Income before income taxes	130,601	39,650
Goodwill	251,808us-gaap_Goodwill		251,808us-gaap_Goodwill
Total assets	12,562,894us-gaap_Assets		9,242,416us-gaap_Assets
Operating segment \| Banking
Information about the revenues, operating results, goodwill and assets
Net interest income (expense)	83,442	79,572
Provision for loan losses	2,486	3,228
Noninterest income	58,775	16,228
Noninterest expense	58,532	60,677
Income before income taxes	81,199	31,895
Goodwill	207,741		207,741
Total assets	8,373,160		8,036,729
Operating segment \| Broker-Dealer
Information about the revenues, operating results, goodwill and assets
Net interest income (expense)	7,996	2,629
Provision for loan losses	201	14
Noninterest income	122,877	24,597
Noninterest expense	90,795	27,365
Income before income taxes	39,877	(153)
Goodwill	7,008		7,008
Total assets	3,747,053		758,636
Operating segment \| Mortgage origination
Information about the revenues, operating results, goodwill and assets
Net interest income (expense)	(3,014)	(4,139)
Noninterest income	135,292	91,763
Noninterest expense	122,302	90,632
Income before income taxes	9,976	(3,008)
Goodwill	13,071		13,071
Total assets	1,412,742		1,498,846
Operating segment \| Insurance
Information about the revenues, operating results, goodwill and assets
Net interest income (expense)	757	980
Noninterest income	41,845	42,773
Noninterest expense	33,466	32,341
Income before income taxes	9,136	11,412
Goodwill	23,988		23,988
Total assets	343,959		328,693
Corporate
Information about the revenues, operating results, goodwill and assets
Net interest income (expense)	109	1,692
Noninterest expense	9,626	2,188
Income before income taxes	(9,517)	(496)
Total assets	1,810,205		1,522,655
All Other and Eliminations.
Information about the revenues, operating results, goodwill and assets
Net interest income (expense)	4,102	4,687
Noninterest income	(4,417)	(5,261)
Noninterest expense	(245)	(574)
Income before income taxes	(70)
Total assets	$ (3,124,225)		$ (2,903,143)

Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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