Mortgage Banking Activities, Components of Loans Held For Sale (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2012	Mar. 31, 2011	Dec. 31, 2011
Mortgage Banking Activities [Abstract]
General number of days outstanding for residential mortgage commitments, minimum (in days)	60D
General number of days outstanding for residential mortgage commitments, maximum (in days)	90D
General number of days for delivery of loans, for which the price is set by forward sales contracts, minimum (in days)	60D
General number of days for delivery of loans, for which the price is set by forward sales contracts, maximum (in days)	90D
Number of days for past due loans (in days)	90D
Schedule of Residential Mortgage Loans Held For Sale [Line Items]
Components of Residential Mortgages Held For Sale Gross, Fair Value	$ 247,039	$ 127,119	$ 188,125
Originating and marketing revenue:
Total originating and marketing revenue	23,081	7,529
Servicing revenue	9,997	9,827
Mortgage banking revenue	33,078	17,356
Residential Mortgage Loans Held For Sale Gross [Member]
Schedule of Residential Mortgage Loans Held For Sale [Line Items]
Residential Mortgage Loans Held For Sale Unpaid Principal Balance, Gross	230,241	120,939	177,319
Components of Residential Mortgages Held For Sale Gross, Fair Value	237,741	124,182	184,816
Originating and marketing revenue:
Total originating and marketing revenue	17,092	13,336
Residential Mortgage Loan Commitments [Member]
Schedule of Residential Mortgage Loans Held For Sale [Line Items]
Components of Residential Mortgages Held For Sale Gross, Fair Value	8,907	3,495	6,597
Residential Mortgage Derivatives Notional Amount	302,303	158,946	189,770
Originating and marketing revenue:
Total originating and marketing revenue	2,310	1,244
Forward Sales Contracts[Member]
Schedule of Residential Mortgage Loans Held For Sale [Line Items]
Components of Residential Mortgages Held For Sale Gross, Fair Value	391	(558)	(3,288)
Residential Mortgage Derivatives Notional Amount	520,165	262,977	349,447
Originating and marketing revenue:
Total originating and marketing revenue	$ 3,679	$ (7,051)

Maximum number of days for delivery of forward sales contracts.

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Maximum number of days outstanding for residential mortgage commitments to purchase.

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Minimum number of days for delivery of forward sales contracts.

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Minimum number of days outstanding for residential mortgage commitments to purchase.

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Noninterest income derived from the sale and changes in fair value of residential mortgage loans held for sale and fees for servicing of residential mortgage loans held by third parties. Also includes changes in the fair value of residential mortgage loan commitments and forward sales commitments considered to be derivative instruments.

+ References

No definition available.

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- Definition

Number of days past due for residential mortgage loans

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- Definition

Total gain (loss) on mortgage loans held for sale, including mortgage loan commitments and forward sales contracts.

+ References

No definition available.

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- Definition

Unpaid principal balance of loans held for sale.

+ References

No definition available.

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Carrying amount of mortgage loans to individuals not classified as held for investment but are held-for-sale.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 948

-SubTopic 310

-Section 45

-Paragraph 1

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-Topic 942

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-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.7(a)(3))

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-Name Federal Regulation (FR)

-Number Title 12

-Chapter V

-Section 563c.102

-Subsection I

-Paragraph 8

-Subparagraph h

-LegacyDoc This is a non-GAAP reference that was included in the 2009 taxonomy. It will be removed from future versions of this taxonomy.

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Permanent Investor

-URI http://asc.fasb.org/extlink&oid=6520390

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-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 65

-Paragraph 1, 34

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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- Definition

Aggregate notional amount of all derivatives. The notional amount relates to a number of currency units, shares, bushels, pounds, or other units specified in a derivative instrument.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

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Income from servicing real estate mortgages, credit cards, and other financial assets held by others. Also include any premiums received in lieu of regular servicing fees on such loans only as earned over the life of the loans. May also be net of any related impairment of fair value of capitalized service costs.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher OTS

-Name Federal Regulation (FR)

-Number Title 12

-Chapter V

-Section 563c.102

-Paragraph 13

-Subsection II

-LegacyDoc This is a non-GAAP reference that was included in the 2009 taxonomy. It will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Paragraph 13

-Article 9

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 225

-Section S99

-Paragraph 1

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