Preferred Stock (Components Of Dividends Declared And Undeclared And In Kind Dividends Deemed On Preferred Stock) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Dividends Payable [Line Items]
Dividends declared and undeclared and in kind dividends deemed on preferred stock	$ 12,243	$ 20,748	$ 3,632
Accrued At Stated Rate [Member] | Series A Preferred Stock [Member]
Dividends Payable [Line Items]
Dividends declared and undeclared and in kind dividends deemed on preferred stock		222	727
Accrued At Stated Rate [Member] | Series B Preferred Stock [Member]
Dividends Payable [Line Items]
Dividends declared and undeclared and in kind dividends deemed on preferred stock		243	831
Accrued At Stated Rate [Member] | Series C Preferred Stock [Member]
Dividends Payable [Line Items]
Dividends declared and undeclared and in kind dividends deemed on preferred stock		455	$ 2,074
Accrued At Stated Rate [Member] | Series D Preferred Stock [Member]
Dividends Payable [Line Items]
Dividends declared and undeclared and in kind dividends deemed on preferred stock	650	3,090
Accrued At Stated Rate [Member] | Series E Preferred Stock [Member]
Dividends Payable [Line Items]
Dividends declared and undeclared and in kind dividends deemed on preferred stock	483
Deemed Upon Notice Of Redemption [Member] | Series A Preferred Stock [Member]
Dividends Payable [Line Items]
Dividends declared and undeclared and in kind dividends deemed on preferred stock		652
Deemed Upon Notice Of Redemption [Member] | Series B Preferred Stock [Member]
Dividends Payable [Line Items]
Dividends declared and undeclared and in kind dividends deemed on preferred stock		668
Deemed At Exchange [Member] | Series C Preferred Stock [Member]
Dividends Payable [Line Items]
Dividends declared and undeclared and in kind dividends deemed on preferred stock		$ 15,418
Inducement To Convert [Member] | Series D Preferred Stock [Member]
Dividends Payable [Line Items]
Dividends declared and undeclared and in kind dividends deemed on preferred stock	$ 11,110