Net Income Per Common Share (Narrative) (Details) - USD ($)	3 Months Ended	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2020	Jun. 30, 2019
Earnings Per Share [Abstract]
Issuance of preferred stock	$ 395,000,000	$ 395,000,000	$ 0
Depositary Shares, Issued	400,000	400,000
Preferred Stock, Dividend Rate, Percentage		5.625%
Preferred Stock, Liquidation Preference, Value	$ 100,000	$ 100,000
Preferred Stock, Liquidation Preference Per Share	$ 1,000	$ 1,000
Proceeds from Issuance of Preferred Stock, Preference Stock, and Warrants		$ 400,000,000