Net Loss Per Share (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2018	Jun. 30, 2017
Stock Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares excluded from the computation of diluted earnings per share (in shares)	1,334,000	1,334,000	2,664,000
Non-Employee Directors' Deferred Fee Plan and Equity Plan [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares excluded from the computation of diluted earnings per share (in shares)		247,634	155,616
Expense recognized during the period		$ 0	$ (3)
Series A Preferred Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares excluded from the computation of diluted earnings per share (in shares)		19,250,000	19,250,000