Condensed Consolidated Balance Sheets - USD ($)	Jun. 30, 2023	Dec. 31, 2022
Current Assets:
Cash and cash equivalents	$ 4,286,000	$ 3,372,000
Trade accounts receivable, net of allowance for doubtful accounts of $466 and $338, respectively	20,872,000	14,668,000
Inventory	27,960,000	23,414,000
Federal income tax receivable (Note 4)	11,538,000	11,538,000
Prepaid income taxes	10,000	10,000
Prepaid expenses and other	1,446,000	1,145,000
Total current assets	66,112,000	54,147,000
Long-term inventory, net of allowance for obsolescence of $40 and $120, respectively	2,157,000	1,557,000
Rental equipment, net of accumulated depreciation of $187,580 and $177,729, respectively	326,691,000	246,450,000
Property and equipment, net of accumulated depreciation of $17,533 and $16,981, respectively	21,382,000	22,176,000
Right of use assets - operating leases, net of accumulated amortization $815 and $721, respectively	310,000	349,000
Intangibles, net of accumulated amortization of $2,322 and $2,259, respectively	837,000	900,000
Other assets	4,996,000	2,667,000
Total assets	422,485,000	328,246,000
Current Liabilities:
Accounts payable	28,603,000	6,481,000
Accrued liabilities	18,492,000	23,726,000
Current operating leases	133,000	155,000
Deferred income	0	37,000
Total current liabilities	47,228,000	30,399,000
Long-term debt	100,011,000	25,000,000
Deferred income tax liability	40,194,000	39,798,000
Long-term operating leases	177,000	194,000
Other long-term liabilities	3,290,000	2,779,000
Total liabilities	190,900,000	98,170,000
Commitments and contingencies (Note 9)
Stockholders’ Equity:
Preferred stock, 5,000 shares authorized, no shares issued or outstanding	0	0
Common stock, 30,000 shares authorized, par value $0.01; 13,688 and 13,519 shares issued, respectively	136,000	135,000
Additional paid-in capital	116,045,000	115,411,000
Retained earnings	130,408,000	129,534,000
Treasury shares, at cost, 1,310 shares	(15,004,000)	(15,004,000)
Total stockholders' equity	231,585,000	230,076,000
Total liabilities and stockholders' equity	$ 422,485,000	$ 328,246,000

Rental Equipment, Net

No definition available.

Name:	ngs_RentalEquipmentNet
Namespace Prefix:	ngs_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Carrying value as of the balance sheet date of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).