Debt (Details) - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Jul. 24, 2017	Dec. 21, 2016
Debt
Maximum borrowing capacity						$ 50,000,000
Net discount on debt and deferred financing fees			$ (92,000)
Long-term Debt, Total		$ 17,227,000	27,381,000
Less current maturities of long-term debt		(44,000)	(2,223,000)
Long-term debt		17,183,000	25,158,000
Long-term Debt, Fiscal Year Maturity [Abstract]
2018		44,000
2019		15,372,000
2020		48,000
2021		50,000
2022		52,000
Thereafter		1,661,000
Loss on debt extinguishment			(1,681,000)	$ (1,449,000)
Revolving credit facility
Debt
Maximum borrowing capacity						45,000,000
Aggregate principal amount		25,000,000
Outstanding balance		$ 15,325,000	22,473,000
Variable interest rate, basis points spread over variable reference rate (as a percent)		5.00%
Term loans
Debt
Maximum borrowing capacity						$ 5,000,000
Aggregate principal amount	$ 48,000
Outstanding balance		$ 0	$ 5,000,000
Variable interest rate, basis points spread over variable reference rate (as a percent)			4.25%
Term B Loans
Debt
Aggregate principal amount			$ 3,000,000
Term A Loans
Debt
Aggregate principal amount		20,000,000
Mortgage
Debt
Mortgage		$ 1,902,000
Fixed interest rate					4.35%
Amended Credit Agreement
Long-term Debt, Fiscal Year Maturity [Abstract]
Debt issuance costs	218,000
Loss on debt extinguishment	$ 993,000
New Credit Agreement
Long-term Debt, Fiscal Year Maturity [Abstract]
Debt issuance costs			261,000
Loss on debt extinguishment			$ 688,000