Fair Value Measurements (Details 6) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014	Dec. 31, 2013
Financial assets:
Held to maturity securities	$ 186,032	$ 118,345	$ 118,345
Non-covered loans, net	4,795,322	3,883,435
Covered loans	550,626	638,029
Broker-dealer and clearing organization receivables	2,222,517	167,884
FDIC indemnification asset	107,567us-gaap_FDICIndemnificationAsset	130,437us-gaap_FDICIndemnificationAsset	188,736us-gaap_FDICIndemnificationAsset	188,291us-gaap_FDICIndemnificationAsset
Financial liabilities:
Broker-dealer and clearing organization payables	1,951,040	179,042
Level 1
Financial assets:
Cash and cash equivalents	708,533	813,075
Level 2
Financial assets:
Held to maturity securities	186,032	118,345
Loans held for sale	27,056	37,541
Non-covered loans, net	608,554	378,425
Broker-dealer and clearing organization receivables	2,222,517	167,884
Other assets	45,784	43,937
Financial liabilities:
Deposits	7,138,613	6,365,555
Broker-dealer and clearing organization payables	1,951,040	179,042
Short-term borrowings	999,476	762,696
Debt	169,024	117,028
Other liabilities	2,095	2,144
Level 3
Financial assets:
Non-covered loans, net	4,605,859	3,528,769
Covered loans	704,848	767,751
FDIC indemnification asset	107,567	130,437
Other assets	15,578	15,495
Estimate of Fair Value Measurement
Financial assets:
Cash and cash equivalents	708,533	813,075
Held to maturity securities	186,032	118,345
Loans held for sale	27,056	37,541
Non-covered loans, net	5,214,413	3,907,194
Covered loans	704,848	767,751
Broker-dealer and clearing organization receivables	2,222,517	167,884
FDIC indemnification asset	107,567	130,437
Other assets	61,362	59,432
Financial liabilities:
Deposits	7,138,613	6,365,555
Broker-dealer and clearing organization payables	1,951,040	179,042
Short-term borrowings	999,476	762,696
Debt	169,024	117,028
Other liabilities	2,095	2,144
Carrying Amount
Financial assets:
Cash and cash equivalents	708,533	813,075
Held to maturity securities	183,792	118,209
Loans held for sale	27,056	37,541
Non-covered loans, net	4,795,322	3,883,435
Covered loans	550,626	638,029
Broker-dealer and clearing organization receivables	2,222,517	167,884
FDIC indemnification asset	107,567	130,437
Other assets	61,362	59,432
Financial liabilities:
Deposits	7,129,277	6,369,892
Broker-dealer and clearing organization payables	1,951,040	179,042
Short-term borrowings	999,476	762,696
Debt	175,694	123,696
Other liabilities	$ 2,095	$ 2,144

Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

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Carrying amount of receivable assets originating from the indemnification agreement with the Federal Deposit Insurance Corporation (FDIC), in which the FDIC is to partially cover losses.

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Fair value of investments in debt securities classified as held-to-maturity.

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Amount after allowance and deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements and loans held for sale.

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The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission.

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