Organization and Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2015

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
2013	$	460	$	1,175	$	(446	)	$	1,189
2014	$	1,189	$	1,099	$	(366	)	$	1,922
2015	$	1,922	$	—	$	(150	)	$	1,772

Schedule of Accumulated Other Comprehensive Income (Loss)

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

	December 31,
	2015			2014
Foreign currency translation
Balance at beginning of period	$	(471	)	$	18
Other comprehensive (loss) income:
Foreign currency translation adjustments (1)	(1,097		)	(489		)
Balance at end of period	$	(1,568	)	$	(471	)
Available-for-sale marketable securities
Balance at beginning of period	$	23		$	19
Other comprehensive income (loss):
Net unrealized holding gain (loss) (2)	(11		)	4
Deferred income taxes (2)	—			—
Total other comprehensive income (loss)	(11		)	4
Balance at end of period	$	12		$	23
Total accumulated other comprehensive (loss) income	$	(1,556	)	$	(448	)

(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 following table shows our goodwill activity by reporting unit during the periods ending December 31, 2015 and 2014:

	2015
Reporting Unit	Beginning Carrying Amount		Acquired Goodwill		Impairment Charge			Ending Carrying Amount
FUEL CHEM Technology Segment	$	2,116	$	—	$	—		$	2,116
APC Technology Segment	—		—		—			—
	$	2,116	$	—	$	—		$	2,116
	2014
Reporting Unit	Beginning Carrying Amount		Acquired Goodwill		Impairment Charge			Ending Carrying Amount
FUEL CHEM Technology Segment	$	2,116	$	—	$	—		$	2,116
APC Technology Segment	18,935		4,465		(23,400		)	—
	$	21,051	$	4,465	$	(23,400	)	$	2,116

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, 2015 and 2014, and the accumulated amortization and net intangible asset value in total for all other intangible assets.

		2015							2014
Description of Other Intangibles	Amortization Period	Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount		Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount
Customer relationships	4-15 years	$	3,633	$	(3,114	)	$	519	$	5,087	$	(2,690	)	$	2,397
Trademarks and trade names	4-8 years	441		(382		)	59		441		(293		)	148
Patent assets	1-15 years	3,007		(1,210		)	1,797		2,764		(987		)	1,777
Acquired technologies	5-8 years	7,515		(2,746		)	4,769		7,974		(1,832		)	6,142
Total		$	14,596	$	(7,452	)	$	7,144	$	16,266	$	(5,802	)	$	10,464

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
2016	$	1,700
2017	1,374
2018	1,269
2019	1,016
2020	564
Thereafter	1,221
Total	$	7,144

Property, Plant and Equipment

The table below shows the depreciable life and cost by asset class as of December 31, 2015 and 2014, and the accumulated depreciation and net book value in total for all classes of assets.

Description of Property and Equipment	Depreciable Life	2015			2014
Land		$	1,440		$	1,440
Building	39 years	4,535			4,535
Building and leasehold improvements	3-39 years	5,102			5,115
Field equipment	3-4 years	19,797			19,796
Computer equipment and software	2-3 years	2,978			3,005
Furniture and fixtures	3-10 years	1,527			1,525
Vehicles	5 years	36			36
Total cost		35,415			35,452
Less accumulated depreciation		(23,414		)	(21,925		)
Total net book value		$	12,001		$	13,527

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:

	2015	2014	2013
Basic weighted-average shares	23,101,000	22,782,000	22,286,000
Conversion of unsecured loan notes	—	—	7,000
Unexercised options and unvested restricted stock units	—	—	286,000
Diluted weighted-average shares	23,101,000	22,782,000	22,579,000