Organization and Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2017

Accounting Policies [Abstract]

Allowance for Credit Losses on Financing Receivables

The table below sets forth the components of the Allowance for Doubtful Accounts for the years ended December 31.

Year	Balance at January 1		Provision charged to expense		Write-offs / Recoveries			Balance at December 31
2015	$	1,922	$	—	$	(150	)	$	1,772
2016	$	1,772	$	172	$	(375	)	$	1,569
2017	$	1,569	$	—	$	(24	)	$	1,545

Schedule of Excess and Obsolete Inventory Reserve

The table below sets forth the components of the Excess and Obsolete Inventory Reserve for the years ended December 31.

Year	Balance at January 1		Provision charged to expense		Write-offs / Recoveries		Balance at December 31
2016	$	—	$	825	$	—	$	825
2017	$	825	$	228			$	1,053

Schedule of Accumulated Other Comprehensive Income (Loss)

The changes in accumulated other comprehensive (loss) by component were as follows:

	December 31,
	2017			2016
Foreign currency translation
Balance at beginning of period	$	(1,574	)	$	(1,568	)
Other comprehensive (loss):
Foreign currency translation adjustments (1)	802			(6		)
Balance at end of period	$	(772	)	$	(1,574	)
Available-for-sale marketable securities
Balance at beginning of period	$	6		$	12
Other comprehensive (loss):
Net unrealized holding (loss) (2)	(2		)	(6		)
Balance at end of period	$	4		$	6
Total accumulated other comprehensive (loss)	$	(768	)	$	(1,568	)

(1) In all periods presented, there were no tax impacts related to rate changes and no amounts were reclassified to earnings.

(2) In all periods presented, there were no realized holding gains or losses and therefore no amounts were reclassified to earnings.

Schedule of Goodwill

The entire goodwill balance of $2,116 was allocated to the FUEL CHEM technology segment as of December 31, 2017 and 2016. The Company did not recognize a charge for goodwill impairment for the periods ended December 31, 2017, 2016 and 2015.

Schedule of Finite-Lived Intangible Assets

The table below shows the amortization period and other intangible asset cost by intangible asset as of December 31, 2017 and 2016, and the accumulated amortization and net intangible asset value in total for all other intangible assets.

		2017							2016
Description of Other Intangibles	Amortization Period	Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount		Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount
Customer relationships	11-15 years	$	1,198	$	(1,138	)	$	60	$	3,119	$	(2,979	)	$	140
Patent assets	1- 20 years	2,412		(801		)	1,611		3,100		(1,444		)	1,656
Total		$	3,610	$	(1,939	)	$	1,671	$	6,219	$	(4,423	)	$	1,796

Schedule of Finite-Lived Intangible Assets, Future Amortization Expense

The table below shows the estimated future amortization expense for intangible assets:

Year	Estimated Amortization Expense
2018	$	198
2019	138
2020	138
2021	138
2022	138
Thereafter	921
Total	$	1,671

Property, Plant and Equipment

The table below shows the depreciable life and cost by asset class as of December 31, 2017 and 2016, and the accumulated depreciation and net book value in total for all classes of assets.

Description of Property and Equipment	Depreciable Life	2017			2016
Land		$	1,050		$	1,440
Building	39 years	3,950			4,535
Building and leasehold improvements	3-39 years	3,264			5,087
Field equipment	3-4 years	19,251			19,467
Computer equipment and software	2-3 years	3,124			2,973
Furniture and fixtures	3-10 years	1,539			1,521
Vehicles	5 years	32			36
Total cost		32,210			35,059
Less accumulated depreciation		(25,938		)	(24,542		)
Total net book value		$	6,272		$	10,517

Schedule of Earnings Per Share, Basic and Diluted

The table below sets forth the weighted-average shares used at December 31 in calculating earnings (loss) per share:

	2017	2016	2015
Basic weighted-average shares	23,872,000	23,365,000	23,101,000
Conversion of unsecured loan notes	—	—	—
Unexercised options and unvested restricted stock units	—	—	—
Diluted weighted-average shares	23,872,000	23,365,000	23,101,000