Declaration of Dividends (Details) (USD $)	3 Months Ended	1 Months Ended	3 Months Ended	1 Months Ended
Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Oct. 31, 2013 Subsequent Event [Member]	Sep. 30, 2013 Series C Preferred Stock [Member]	Jun. 30, 2013 Series C Preferred Stock [Member]	Mar. 31, 2013 Series C Preferred Stock [Member]	Oct. 31, 2013 Series C Preferred Stock [Member] Subsequent Event [Member]
Dividends Payable [Line Items]
Dividends on common stock (in dollars per share)	$ 0.08	$ 0.08	$ 0.07	$ 0.08
Dividends payable recorded date	Sep. 16, 2013	Jun. 14, 2013	Mar. 15, 2013	Dec. 16, 2013	Oct. 01, 2013	Jul. 01, 2013	Apr. 01, 2013	Jan. 02, 2014
Dividends payable declared date	Jul. 24, 2013	May 22, 2013	Jan. 31, 2013	Oct. 16, 2013	Jul. 24, 2013	May 22, 2013	Jan. 31, 2013	Oct. 16, 2013
Dividends payable, date to be paid	Oct. 01, 2013	Jul. 01, 2013	Apr. 01, 2013	Jan. 02, 2014	Oct. 15, 2013	Jul. 15, 2013	Apr. 15, 2013	Jan. 15, 2014
Preferred stock dividend rate (in hundredth)					1.00%	1.00%	1.00%	1.00%

Aggregate dividends declared during the period for each share of common stock outstanding.

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Article 3

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.3-04)

-URI http://asc.fasb.org/extlink&oid=6959260&loc=d3e187085-122770

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Date the declared dividend will be paid, in CCYY-MM-DD format.

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Date the dividend to be paid was declared, in CCYY-MM-DD format.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 50

-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=6367179&loc=d3e4304-108586

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 32

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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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Date the holder must own the stock to be entitled to the dividend, in CCYY-MM-DD format.

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The percentage rate used to calculate dividend payments on preferred stock.

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