Subsequent Events (Details) (Declaration of Dividends [Member], USD $)	9 Months Ended	3 Months Ended
Sep. 30, 2013	Sep. 30, 2013 Common Stock [Member]	Sep. 30, 2013 Series J Preferred Stock [Member]	Sep. 30, 2013 Series K Preferred Stock [Member]	Sep. 30, 2013 Series L Preferred Stock [Member]
Subsequent Event [Line Items]
Common stock dividends declared per share		$ 0.17
Preferred stock dividends declared per share			$ 0.414063	$ 0.406250	$ 0.412500
Record date		Nov. 14, 2013	Nov. 14, 2013	Nov. 14, 2013	Nov. 14, 2013
Payment date		Nov. 29, 2013	Nov. 29, 2013	Nov. 29, 2013	Nov. 29, 2013
Declared date	Oct. 30, 2013

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=27012166&loc=d3e187085-122770

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+ 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

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