Mortgage Banking Activities - Additional Information (Detail) (USD $)	3 Months Ended
Mar. 31, 2014 Office	Mar. 31, 2013
Mortgage Loans on Real Estate [Line Items]
Number of loan production offices	53
Origination of conforming single family residential mortgage loans held for sale	$ 511,500,000	$ 332,800,000
Conforming single family residential mortgage loans sold	531,800,000	331,700,000
Net gain on sale of mortgage loans held for sale	15,200,000	15,400,000
Margin on sale of mortgage loans held for sale	2.96%	4.61%
Loan origination fees	2,100,000	1,800,000
Initial capitalized value of our MSRs		783,000
Provision for loss reimbursement on sold loans	571,000	256,000
Fannie Mae and Freddie Mac
Mortgage Loans on Real Estate [Line Items]
Proceeds from the sale of mortgage loans held for sale	$ 4,800,000

Loans and Leases Receivable, Origination Fees

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- Definition

Margin Rate

+ References

No definition available.

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- Definition

Number of loan production offices included in Nature of Operations disclosure.

+ References

No definition available.

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- Definition

Provision charged for the period based on estimated losses for sold loans that may have to be subsequently repurchased and amounts that may have to be paid to reimburse certain investor losses due to defects that occurred in the origination of the loans.

+ References

No definition available.

+ Details

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- Definition

The gains (losses) included in earnings that represent the difference between the sale price and the carrying value of loans made to finance real estate acquisitions. This element refers to the gain (loss) and not to the cash proceeds of the sale. This element is a noncash adjustment to net income when calculating net cash generated by operating activities using the indirect method.

+ References

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- Definition

The increase (decrease) during the reporting period in the value of mortgage loans that are held with the intention to sell or be securitized in the near future.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Investing Activities

-URI http://asc.fasb.org/extlink&oid=6516133

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- Definition

The carrying amount of mortgage loans on real estate that were sold during the reporting period.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 205

-SubTopic 10

-Section S99

-Paragraph 6

-Subparagraph (SX 210.5-04.(c) Schedule IV)

-URI http://asc.fasb.org/extlink&oid=27047687&loc=d3e5864-122674

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 29

-Article 12

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Paragraph c

-Subparagraph Schedule IV

-Article 5

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 948

-SubTopic 310

-Section S99

-Paragraph 1

-Subparagraph (SX 210.12-29.6)

-URI http://asc.fasb.org/extlink&oid=6589523&loc=d3e617274-123014

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- Definition

The cash inflow from sales of loans that are secured with real estate mortgages and are held with the intention to resell in the near future.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 21

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3461-108585

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 25

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3536-108585

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- Definition

The value of new servicing assets, subsequently measured at fair value, acquired or created during the current period through purchases or from transfers of financial assets.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 860

-SubTopic 50

-Section 50

-Paragraph 3

-Subparagraph (a)(2)

-URI http://asc.fasb.org/extlink&oid=7882072&loc=d3e122625-111746

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