Long-Term Debt (Credit Facility) (Narrative) (Details) - USD ($)	9 Months Ended
	Sep. 30, 2018	Aug. 03, 2018	Mar. 09, 2018	Dec. 31, 2017
Line of Credit Facility [Line Items]
Maximum secured borrowing capacity	$ 110,000,000
Percentage of maximum secured borrowing capacity	12.50%
Net deferred financing fees	$ 1,659,000			$ 749,000
Amortization of deferred financing costs	200,000
Proceeds under New Markets Tax Credit financing	$ 2,835,000
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%
Amended and Restated Prior Credit Agreement [Member] | PNC Bank [Member]
Line of Credit Facility [Line Items]
Debt instrument, expiration date	Aug. 03, 2023
Revolving Credit Facility [Member] | PNC Bank [Member]
Line of Credit Facility [Line Items]
Commitment fee on the daily unused portion of the Revolver	0.25%
Net deferred financing fees	$ 1,000,000
Revolving Credit Facility [Member] | PNC Bank [Member] | Restricted Cash
Line of Credit Facility [Line Items]
Proceeds under New Markets Tax Credit financing	2,200,000
Revolving Credit Facility [Member] | PNC Bank [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
Revolving Credit Facility [Member] | PNC Bank [Member] | LIBOR [Member]
Line of Credit Facility [Line Items]
Debt instrument, effective interest rate	3.61%
Revolving Credit Facility [Member] | Amended and Restated Prior Credit Agreement [Member] | PNC Bank [Member]
Line of Credit Facility [Line Items]
Maximum secured borrowing capacity		$ 110,000,000
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	4.11%
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