Fair Value Measurements and Derivative Instruments (Reconciliation of Items Measured at Fair Value on a Recurring Basis) (Details) - Level 3 [Member] - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value, beginning of period	$ (692)	$ (769)	$ (711)	$ (755)
Net gains (losses) recognized in earnings	18	(15)	37	(29)
Fair value, end of period	(674)	(784)	(674)	(784)
Total unrealized gains (losses) during the period included in earnings related to instruments held at end of period	18	(15)	37	(29)
Series E Preferred Embedded Redemption Option [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value, beginning of period	356	280	289	314
Net gains (losses) recognized in earnings	42	(14)	109	(48)
Fair value, end of period	398	266	398	266
Total unrealized gains (losses) during the period included in earnings related to instruments held at end of period	42	(14)	109	(48)
Convertible Debt [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value, beginning of period	(1,048)	(1,049)	(1,000)	(1,069)
Net gains (losses) recognized in earnings	(24)	(1)	(72)	19
Fair value, end of period	(1,072)	(1,050)	(1,072)	(1,050)
Total unrealized gains (losses) during the period included in earnings related to instruments held at end of period	$ (24)	$ (1)	$ (72)	$ 19