Equity (Details 3) (Series J 8 3/8% Cumulative Redeemable Preferred Stock, USD $) In Millions, except Per Share data, unless otherwise specified	12 Months Ended
Dec. 31, 2013	Dec. 31, 2012
Series J 8 3/8% Cumulative Redeemable Preferred Stock
Equity
Preferred stock stated dividend rate percentage	8.375%	8.375%
Redemption price of preferred stock (in dollars per share)	$ 50.00
Premium received on preferred stock issued	$ 7.5
Preferred stock unamortized premium	$ 4.5	$ 4.9

Value received from shareholders in nonredeemable preferred stock related transactions that are in excess of par value, value contributed to an entity and value received from other stock related transactions. Examples of other stock related transactions include, amongst other, certain costs incurred in issuing equity securities, certain dividends and certain tax-based consequences of share-based payments compensation awards. Includes only nonredeemable preferred stock transactions or transactions related to preferred stock that are redeemable solely at the option of the issuer. May be called contributed capital, capital in excess of par, capital surplus, or paid-in capital.

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 31

-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 210.5-02.30(a)(1),(2))

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

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