Summary of Significant Accounting Policies - Additional Information (Details)			3 Months Ended		6 Months Ended		12 Months Ended
	Mar. 27, 2020 USD ($)	Mar. 26, 2020	Jun. 30, 2020 USD ($) shares	Jun. 30, 2019 USD ($) shares	Jun. 30, 2020 USD ($) segment shares	Jun. 30, 2019 USD ($) shares	Dec. 31, 2019 USD ($)	Jan. 01, 2019 USD ($)	Dec. 31, 2018 USD ($)
Significant Accounting Policies [Line Items]
Number of Reportable Segments | segment					1
Options and warrants excluded from the calculation of diluted shares | shares			5,282,377	4,690,197	7,042,377	4,690,197
Additional tax benefit related to the alternative minimum tax refund			$ 380,000
Operating Loss Carryforwards			45,000,000		$ 45,000,000
Deferred Tax Assets, Valuation Allowance									$ 11,300,000
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount					17,800,000
Goodwill impairment loss					0		$ 0
Cylinder deposit liability					10,300,000		9,500,000
Operating Lease, Right-of-Use Asset			7,205,000		7,205,000		$ 8,048,000
Operating Lease, Liability			7,278,000		7,278,000
No Expiration [Member]
Significant Accounting Policies [Line Items]
Operating Loss Carryforwards			39,600,000		39,600,000
Expiration Through 2023
Significant Accounting Policies [Line Items]
Operating Loss Carryforwards			5,400,000		5,400,000
State and Local Jurisdiction [Member]
Significant Accounting Policies [Line Items]
Operating Loss Carryforwards			24,100,000		$ 24,100,000
ASU Topic 842 [Member]
Significant Accounting Policies [Line Items]
Operating Lease, Right-of-Use Asset								$ 8,100,000
Operating Lease, Liability								$ 8,100,000
Customer Concentration Risk [Member] | One Customer | Revenue from Contract with Customer [Member]
Significant Accounting Policies [Line Items]
Concentration Risk, Percentage					12.00%	13.00%
Customer Concentration Risk [Member] | One Customer | Accounts Receivable
Significant Accounting Policies [Line Items]
Accounts Receivable, net			2,000,000	$ 2,800,000	$ 2,000,000	$ 2,800,000
CARES Act
Significant Accounting Policies [Line Items]
Percent of taxable income offset for taxable years beginning before 2021	100.00%
Preliminary tax benefit related to the alternative minimum tax refund					47,000
Percent of adjusted taxable income	50.00%	30.00%
Increase in allowable interest expense	$ 1,621,000
Operating Loss Carryforwards			$ 1,621,000		$ 1,621,000