Equity and Accumulated Other Comprehensive Loss, Net (Schedule of Dividends) (Details) $ / shares in Units, $ in Thousands	6 Months Ended
	Jun. 30, 2018 USD ($) $ / shares
Series C Preferred Stock
Dividends Payable [Line Items]
Dividends, preferred stock	$ 6,666
Preferred stock dividend per share amount (in dollars per share) | $ / shares	$ 1.65625
Series C Preferred Stock | March 1, 2018 Installment
Dividends Payable [Line Items]
Dividends, preferred stock	$ 3,333
Series C Preferred Stock | May 8, 2018 Installment
Dividends Payable [Line Items]
Dividends, preferred stock	3,333
Series G Preferred Stock
Dividends Payable [Line Items]
Dividends, preferred stock	$ 7,344
Preferred stock dividend per share amount (in dollars per share) | $ / shares	$ 1.46875
Series G Preferred Stock | March 1, 2018 Installment
Dividends Payable [Line Items]
Dividends, preferred stock	$ 3,672
Series G Preferred Stock | May 8, 2018 Installment
Dividends Payable [Line Items]
Dividends, preferred stock	3,672
Series H Preferred Stock
Dividends Payable [Line Items]
Dividends, preferred stock	$ 13,460
Preferred stock dividend per share amount (in dollars per share) | $ / shares	$ 1.84375
Series H Preferred Stock | March 1, 2018 Installment
Dividends Payable [Line Items]
Dividends, preferred stock	$ 6,730
Series H Preferred Stock | May 8, 2018 Installment
Dividends Payable [Line Items]
Dividends, preferred stock	6,730
Series I Preferred Stock
Dividends Payable [Line Items]
Dividends, preferred stock	$ 7,938
Preferred stock dividend per share amount (in dollars per share) | $ / shares	$ 1.5875
Series I Preferred Stock | March 1, 2018 Installment
Dividends Payable [Line Items]
Dividends, preferred stock	$ 3,969
Series I Preferred Stock | May 8, 2018 Installment
Dividends Payable [Line Items]
Dividends, preferred stock	3,969
Series J Preferred Stock
Dividends Payable [Line Items]
Dividends, preferred stock	$ 5,250
Preferred stock dividend per share amount (in dollars per share) | $ / shares	$ 1.3125
Series J Preferred Stock | March 1, 2018 Installment
Dividends Payable [Line Items]
Dividends, preferred stock	$ 2,625
Series J Preferred Stock | May 8, 2018 Installment
Dividends Payable [Line Items]
Dividends, preferred stock	2,625
Common Stock
Dividends Payable [Line Items]
Dividends, common stock	$ 416,086
Common stock dividend per share amount (in dollars per share) | $ / shares	$ 4.04
Common Stock | March 1, 2018 Installment
Dividends Payable [Line Items]
Dividends, common stock	$ 208,015
Common Stock | May 8, 2018 Installment
Dividends Payable [Line Items]
Dividends, common stock	$ 208,071