Equity (Terms of Outstanding Preferred Stock) (Details)		4 Months Ended		7 Months Ended	12 Months Ended
	Nov. 01, 2016 shares	May 07, 2013 shares	Apr. 24, 2012 shares	Jul. 27, 2011 shares	Dec. 31, 2020 votingRightPerShare $ / shares
Series B Preferred Stock
Debt Instrument [Line Items]
Preferred stock, dividend rate (in dollars per share) | $ / shares					$ 1.80
Preferred stock, voting rights | votingRightPerShare					8
Series O Preferred Stock
Debt Instrument [Line Items]
Number of Depositary Shares Issued and Outstanding				1,000,000
Fractional Interest in a share of preferred stock represented by each Depositary Share				1.00%
Preferred stock, dividend rate, percentage				6.75%
Series P Preferred Stock
Debt Instrument [Line Items]
Number of Depositary Shares Issued and Outstanding			60,000,000
Fractional Interest in a share of preferred stock represented by each Depositary Share			0.025%
Preferred stock, dividend rate, percentage			6.125%
Series R Preferred Stock
Debt Instrument [Line Items]
Number of Depositary Shares Issued and Outstanding		500,000
Fractional Interest in a share of preferred stock represented by each Depositary Share		1.00%
Preferred stock, dividend rate, percentage		4.85%
Series S Preferred Stock
Debt Instrument [Line Items]
Number of Depositary Shares Issued and Outstanding	525,000
Fractional Interest in a share of preferred stock represented by each Depositary Share	1.00%
Preferred stock, dividend rate, percentage	5.00%
3-month LIBOR | Series O Preferred Stock
Debt Instrument [Line Items]
Basis spread on variable rate - LIBOR Plus				3.678%
3-month LIBOR | Series P Preferred Stock
Debt Instrument [Line Items]
Basis spread on variable rate - LIBOR Plus			4.0675%
3-month LIBOR | Series R Preferred Stock
Debt Instrument [Line Items]
Basis spread on variable rate - LIBOR Plus		3.04%
3-month LIBOR | Series S Preferred Stock
Debt Instrument [Line Items]
Basis spread on variable rate - LIBOR Plus	3.30%