Represents the number of outstanding short-term FHLB advances.

No definition available.

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- Definition

The cost of acquiring the advances.

+ References

No definition available.

+ Details

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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Weighted average remaining maturity on FHLB advances

+ References

No definition available.

+ Details

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Data Type:	xbrli:durationItemType
Balance Type:	na
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- Definition

Amount of unused borrowing capacity under the long-term financing arrangement that is available to the entity as of the balance sheet date.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22(b))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Subparagraph b

-Article 5

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Interest expense incurred during the reporting period on short-term borrowings associated with Federal Home Loan Bank and Federal Reserve Bank advances.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Reflects the total carrying amount as of the balance sheet date of debt having initial terms less than one year or the normal operating cycle, if longer.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19

-Subparagraph a

-Article 5

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.19(a))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.13)

-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.7-03.(a),16(a)(1))

-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 16

-Subparagraph a(1)

-Article 7

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 13

-Subparagraph 2, 3

-Article 9

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

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Balance Type:	na
Period Type:	duration

- Definition

Weighted average interest rate of short-term debt outstanding.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.19(b))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19

-Subparagraph b

-Article 5

+ Details

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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Details

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- Details

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- Details

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Data Type:	na
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- Details

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- Details

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- Details

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Borrowings (Details) (USD $)	12 Months Ended
Borrowings (Details) (USD $)	Dec. 31, 2014 Loan	Dec. 31, 2013	Dec. 31, 2012
Short-Term Borrowings [Abstract]
Total short-term borrowings	$ 425,077,000us-gaap_ShortTermBorrowings	$ 66,385,000us-gaap_ShortTermBorrowings
Fair Market Value Adjustment [Member]
Short-Term Borrowings [Abstract]
Total short-term borrowings	178,000	28,000
Atlanta [Member]
Short-Term Borrowings [Abstract]
Number of outstanding short-term FHLB advances	2
Interest expense, short-term borrowings	197,000	6,000	81,000
Dallas [Member]
Short-Term Borrowings [Abstract]
Additional debt instrument borrowing capacity	1,678,000,000	1,768,000,000
Federal Home Loan Bank Advances [Member]
Short-Term Borrowings [Abstract]
Total short-term borrowings	356,758,000	2,062,000
Federal Home Loan Bank Advances [Member] \| Atlanta [Member]
Short-Term Borrowings [Abstract]
Number of outstanding short-term FHLB advances		2
Weighted average remaining maturity	297 days	134 days
Weighted average cost related to FHLB advances (in hundredths)	3.96%	4.24%
Federal Home Loan Bank Advances [Member] \| Dallas [Member]
Short-Term Borrowings [Abstract]
Number of outstanding short-term FHLB advances	4
Total short-term borrowings	350,000,000	0
Weighted average remaining maturity	9 days
Weighted average cost related to FHLB advances (in hundredths)	0.14%
Federal Home Loan Bank Advances [Member] \| Dallas [Member] \| Maximum [Member]
Short-Term Borrowings [Abstract]
Total short-term borrowings	100,000,000
Interest rate (in hundredths)	0.18%
Federal Home Loan Bank Advances [Member] \| Dallas [Member] \| Minimum [Member]
Short-Term Borrowings [Abstract]
Total short-term borrowings	50,000,000
Interest rate (in hundredths)	0.10%
Federal Home Loan Bank Advances [Member] \| Advance One [Member] \| Atlanta [Member]
Short-Term Borrowings [Abstract]
Total short-term borrowings	80,000	2,000,000
Interest rate (in hundredths)	6.95%	4.21%
Federal Home Loan Bank Advances [Member] \| Advance Two [Member] \| Atlanta [Member]
Short-Term Borrowings [Abstract]
Total short-term borrowings	6,500,000	34,000
Interest rate (in hundredths)	3.92%	6.11%
Serviced GNMA Loans Eligible for Repurchase [Member]
Short-Term Borrowings [Abstract]
Total short-term borrowings	41,014,000	38,036,000
Other [Member]
Short-Term Borrowings [Abstract]
Total short-term borrowings	$ 27,305,000	$ 26,287,000