Long-Term Debt (Credit Facility) (Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Aug. 03, 2018	Mar. 09, 2018
Line of Credit Facility [Line Items]
Maximum secured borrowing capacity	$ 110,000,000
Percentage of maximum secured borrowing capacity	12.50%
Payments due on notes relevant to minimum liquidity calculation	$ 2,000,000
Net deferred financing fees	1,603,000	$ 749,000
Amortization of deferred financing costs	300,000	300,000	$ 200,000
New Markets Tax Credit (NMTC) Program [Member]
Line of Credit Facility [Line Items]
Net deferred financing fees					$ 700,000
PNC Bank [Member]
Line of Credit Facility [Line Items]
Minimum fixed charge coverage ratio				110.00%
Net deferred financing fees	900,000	700,000
Amortization of deferred financing costs	$ 300,000	$ 300,000
PNC Bank [Member] | Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Commitment fee on the daily unused portion of the Revolver	0.25%
PNC Bank [Member] | Revolving Credit Facility [Member] | Restricted Cash [Member]
Line of Credit Facility [Line Items]
Proceeds under New Markets Tax Credit financing	$ 8,000,000
PNC Bank [Member] | Revolving Credit Facility [Member] | New Markets Tax Credit (NMTC) Program [Member]
Line of Credit Facility [Line Items]
Increase in maximum aggregate principal amount of borrowings	$ 6,700,000
PNC Bank [Member] | Revolving Credit Facility [Member] | LIBOR [Member]
Line of Credit Facility [Line Items]
Debt instrument, effective interest rate	3.85%
Amended and Restated Prior Credit Agreement [Member] | PNC Bank [Member]
Line of Credit Facility [Line Items]
Debt instrument, expiration date	Aug. 03, 2023
Amended and Restated Prior Credit Agreement [Member] | PNC Bank [Member] | Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Maximum secured borrowing capacity				$ 110,000,000
Additional Credit Agreement [Member] | PNC Bank [Member]
Line of Credit Facility [Line Items]
Net deferred financing fees	$ 400,000
Term Loan [Member] | PNC Bank [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Frequency of Periodic Payment	quarterly
Quarterly term loan payments	$ 400,000
Term Loan [Member] | PNC Bank [Member] | LIBOR [Member]
Line of Credit Facility [Line Items]
Debt instrument, effective interest rate	4.35%
Term Loan [Member] | Amended and Restated Prior Credit Agreement [Member] | PNC Bank [Member]
Line of Credit Facility [Line Items]
Maximum secured borrowing capacity				$ 10,000,000