Stockholders' Equity - Cash Dividends Declared - Preferred Stock (Details) - $ / shares	Jul. 15, 2020	Jan. 15, 2020	Oct. 15, 2019	Jul. 15, 2019	Apr. 15, 2019
Series B Preferred Stock
Dividends Payable [Line Items]
Cash Dividend Per Share (in dollars per share)		$ 0.484375	$ 0.484375	$ 0.484375	$ 0.484375
Series C Preferred Stock
Dividends Payable [Line Items]
Cash Dividend Per Share (in dollars per share)		0.4921875	0.4921875	0.4921875	0.4921875
Series D Preferred Stock
Dividends Payable [Line Items]
Cash Dividend Per Share (in dollars per share)		0.50	$ 0.50	$ 0.50	$ 0.50
Series E Preferred Stock
Dividends Payable [Line Items]
Cash Dividend Per Share (in dollars per share)		$ 0.47578
Subsequent Event | Series B Preferred Stock
Dividends Payable [Line Items]
Cash Dividend Per Share (in dollars per share)	$ 0.96875
Subsequent Event | Series C Preferred Stock
Dividends Payable [Line Items]
Cash Dividend Per Share (in dollars per share)	0.984375
Subsequent Event | Series D Preferred Stock
Dividends Payable [Line Items]
Cash Dividend Per Share (in dollars per share)	1.00
Subsequent Event | Series E Preferred Stock
Dividends Payable [Line Items]
Cash Dividend Per Share (in dollars per share)	$ 0.984375