v2.4.0.8

Equity - Narrative (Details) | 6 Months Ended
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Jun. 30, 2014
5.0% Cumulative Convertible Preferred Stock Series Two Thousand And Five B [Member] |
Schedule of Capitalization, Equity [Line Items] |
Preferred Stock, Dividend Rate, Percentage | 5.00%
4.50% Cumulative Convertible Preferred Stock [Member] |
Schedule of Capitalization, Equity [Line Items] |
Preferred Stock, Dividend Rate, Percentage | 4.50%
5.75% Cumulative Convertible Preferred Stock [Member] |
Schedule of Capitalization, Equity [Line Items] |
Preferred Stock, Dividend Rate, Percentage | 5.75%

X
- Definition The percentage rate used to calculate dividend payments on preferred stock. + References No definition available. + Details
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Balance Type: | na
Period Type: | duration

X
- Details
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Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration