Summary of Significant Accounting Policies - Additional Information (Details)			1 Months Ended	3 Months Ended		12 Months Ended
	Mar. 27, 2020 USD ($)	Mar. 26, 2020	Jul. 31, 2016	Jun. 30, 2020 USD ($)	Mar. 31, 2020 USD ($)	Dec. 31, 2020 USD ($) segment shares	Dec. 31, 2019 USD ($) shares	Jan. 01, 2019 USD ($)	Dec. 31, 2018 USD ($)
Significant Accounting Policies [Line Items]
Number of Reportable Segments | segment						1
Goodwill impairment loss						$ 0	$ 0
Operating Lease, Right-of-Use Asset						6,559,000	8,048,000
Operating Lease, Liability						6,630,000	8,106,000
Cylinder deposit liability						10,800,000	9,500,000
Contract term			5 years
Contract renewal term			5 years
Additional tax benefit related to the alternative minimum tax refund				$ 380,000
Operating Loss Carryforwards						46,100,000
Deferred Tax Assets, Valuation Allowance						19,033,000	$ 18,918,000		$ 11,300,000
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount						$ 19,000,000
Options and warrants excluded from the calculation of diluted shares | shares						5,329,515	7,042,377
No Expiration [Member]
Significant Accounting Policies [Line Items]
Operating Loss Carryforwards						$ 40,700,000
Expiring Through 2023 [Member]
Significant Accounting Policies [Line Items]
Operating Loss Carryforwards						5,400,000
State and Local Jurisdiction [Member]
Significant Accounting Policies [Line Items]
Operating Loss Carryforwards						$ 31,200,000
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						14.00%	14.00%
Customer Concentration Risk [Member] | One Customer | Accounts Receivable
Significant Accounting Policies [Line Items]
Accounts Receivable, net						$ 2,900,000	$ 1,800,000
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	$ 2,154,000
Operating Loss Carryforwards						$ 2,154,000