Equity and Mezzanine Securities Equity and Mezzanine Securities, Dividends Payable Table (Details) - USD ($) $ / shares in Units, $ in Millions				3 Months Ended
	Jul. 17, 2017	Jun. 30, 2017	Jun. 16, 2017	Jun. 30, 2017
Common Stock
Dividends Payable [Line Items]
Dividends Payable, Date of Record		Jun. 30, 2017
Dividends per common share				$ 0.67
Preferred Stock [Member]
Dividends Payable [Line Items]
Dividends Payable, Date of Record		Jun. 30, 2017
Preferred Stock, Dividends Per Share, Declared				0.4453125
Series A-4 Preferred Stock
Dividends Payable [Line Items]
Dividends Payable, Date of Record			Jun. 16, 2017
Dividends Payable, Date to be Paid		Jun. 30, 2017
Preferred Stock, Dividends Per Share, Declared				$ 0.40625
Payments of dividends		$ 0.0
Subsequent Event | Common Stock
Dividends Payable [Line Items]
Dividends Payable, Date to be Paid	Jul. 17, 2017
Payments of dividends	$ 0.0
Subsequent Event | Preferred Stock [Member]
Dividends Payable [Line Items]
Dividends Payable, Date to be Paid	Jul. 17, 2017
Payments of dividends	$ 0.0