Organization and Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2019

Accounting Policies [Abstract]

Schedule of Cash, Cash Equivalents and Restricted Cash

The following table provides a reconciliation of cash, cash equivalents, and restricted cash reported within the Consolidated Balance Sheet that sum to the total of the same such amounts shown in the Consolidated Statements of Cash Flows:

	December 31, 2019		December 31, 2018
Cash and cash equivalents	$	10,914	$	12,039
Restricted cash included in current assets	2,080		6,020
Restricted cash included in long-term assets	507		—
Total cash, cash equivalents, and restricted cash shown in the Consolidated Statements of Cash Flows	$	13,501	$	18,059

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
2017	$	1,569	$	—	$	(24	)	$	1,545
2018	$	1,545	$	—	$	(134	)	$	1,411
2019	$	1,411	$	573	$	(168	)	$	1,816

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
2017	825	228	—		1,053
2018	1,053	78	—		1,131
2019	1,131	—	(131	)	1,000

Schedule of Accumulated Other Comprehensive Income (Loss)

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

	December 31,
	2019			2018
Foreign currency translation
Balance at beginning of period	$	(1,285	)	$	(772	)
Other comprehensive (loss):
Foreign currency translation adjustments (1)	(493		)	(513		)
Balance at end of period	$	(1,778	)	$	(1,285	)
Available-for-sale marketable securities
Balance at beginning of period	$	—		$	4
Other comprehensive (loss):
Net unrealized holding (loss) (2)	—			(4		)
Balance at end of period	$	—		$	—
Total accumulated other comprehensive (loss)	$	(1,778	)	$	(1,285	)

(1) In all periods presented, there were no tax impacts related to rate changes and certain foreign currency translation adjustments were reclassified to earnings in 2019. The adjustments reclassified to earnings in 2019 relate to the substantial completion of the liquidation of Fuel Tech S.p.A (Chile) during the fourth quarter of 2019.

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

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, 2019 and 2018, and the accumulated amortization and net intangible asset value in total for all other intangible assets.

		2019							2018
Description of Other Intangibles	Amortization Period	Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount		Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount
Patent assets	1- 20 years	1,897		(991		)	906		2,092		(928		)	1,164
Total		$	1,897	$	(991	)	$	906	$	2,092	$	(928	)	$	1,164

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
2020	$	144
2021	150
2022	116
2023	83
2024	62
Thereafter	351
Total	$	906

Property, Plant and Equipment

The table below shows the depreciable life and cost by asset class as of December 31, 2019 and 2018, and the accumulated depreciation and net book value in total for all classes of assets.

Description of Property and Equipment	Depreciable Life	2019			2018
Land		$	1,050		$	1,050
Building	39 years	3,950			3,950
Building and leasehold improvements	3-39 years	2,886			3,242
Field equipment	3-4 years	19,507			19,541
Computer equipment and software	2-3 years	2,936			3,154
Furniture and fixtures	3-10 years	1,475			1,535
Vehicles	5 years	32			32
Total cost		31,836			32,504
Less accumulated depreciation		(26,174		)	(26,528		)
Total net book value		$	5,662		$	5,976

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:

	2019	2018	2017
Basic weighted-average shares	24,202,000	24,164,000	23,872,000
Conversion of unsecured loan notes	—	—	—
Unexercised options and unvested restricted stock units	—	—	—
Diluted weighted-average shares	24,202,000	24,164,000	23,872,000