The Company And Nature Of Operations (Narrative) (Details)	1 Months Ended		9 Months Ended	12 Months Ended
	Aug. 31, 2018	Mar. 31, 2018	Sep. 30, 2018	Dec. 31, 2017
Series A Fixed-to-Floating Rate Cumulative Redeemable Perpetual Preferred Stock [Member]
Business Acquisition [Line Items]
Preferred stock, dividend rate		8.50%	8.50%	8.50%
Series B Fixed-to-Floating Rate Cumulative Redeemable Perpetual Preferred Stock [Member]
Business Acquisition [Line Items]
Preferred stock, dividend rate	8.50%		8.50%	8.50%