5. Goodwill and Intangible Assets

Goodwill

The Company reviews goodwill for impairment annually as of December 31 and whenever events or changes in circumstances indicate the carrying value of an asset may not be recoverable. The Company tests goodwill at the reporting unit level. A reporting unit is an operating segment, or one level below an operating segment, as defined by U.S. GAAP. After the acquisition of Hyperspring on November 14, 2014, the Company determined that it had two reporting units, which are the same as our two operating segments: (i) Performance Improvement Solutions; and (ii) Nuclear Industry Training and Consulting (which includes Hyperspring and Absolute). As of December 31, 2018 and 2017, goodwill of $13.2 million and $8.4 million, respectively, related to the acquisitions of Hyperspring, Absolute and True North Consulting. No impairment of goodwill was recorded in 2018 or 2017.

The change in the net carrying amount of goodwill from January 1, 2017 through December 31, 2018 was comprised of the following items:

(in thousands)

	Performance Improvement Solutions		Nuclear Industry Training and Consulting		Total
Net book value at January 1, 2017	$	-	$	5,612	$	5,612

Acquisition		-		2,819		2,819
Dispositions		-		-		-
Goodwill impairment loss		-		-		-

Net book value at December 31, 2017	$	-	$	8,431	$	8,431

Acquisition		4,739		-		4,739
Dispositions		-		-		-
Goodwill impairment loss		-		-		-

Net book value at December 31, 2018	$	4,739	$	8,431	$	13,170

Intangible Assets Subject to Amortization

As discussed in Note 2, Acquisitions, we recognized finite-lived intangible assets of $5.1 million upon acquisition of True North on May 11, 2018 and $2.6 million upon acquisition of Absolute on September 17, 2017, including customer contracts and relationships, trademarks, non-compete agreements, and alliance agreements, with amortization periods of four to fifteen years. Amortization is recognized on a straight-line basis over the estimated useful life of the intangible assets. The fair value of the intangible assets is provisional pending receipt of the final valuations for these assets.

The following table shows the gross carrying amount and accumulated amortization of definite-lived intangible assets:

(in thousands)	As of December 31, 2018
	Gross Carrying Amount		Accumulated Amortization			Net
Amortized intangible assets:
Customer relationships	$	6,831	$	(2,375	)	$	4,456
Trade names		1,295		(318	)		977
Developed technology		471		(471	)		-
Non-contractual customer relationships		433		(433	)		-
Noncompete agreement		221		(35	)		186
Alliance agreement		527		(66	)		461
Others		167		(167	)		-
Total	$	9,945	$	(3,865	)	$	6,080

(in thousands)	As of December 31, 2017
	Gross Carrying Amount		Accumulated Amortization			Net
Amortized intangible assets:
Customer relationships	$	3,074	$	(1,218	)	$	1,856
Trade names		713		(33	)		680
Developed technology		471		(412	)		59
Non-contractual customer relationships		433		(426	)		7
Others		167		(165	)		2
Total	$	4,858	$	(2,254	)	$	2,604

Amortization expense related to definite-lived intangible assets totaled $1.6 million and $0.3 million for the years ended December 31, 2018 and 2017, respectively. The following table shows the estimated amortization expense of the definite-lived intangible assets for the next five years:

(in thousands)
Years ended December 31:
2019	$	1,654
2020		1,332
2021		903
2022		674
2023		455
Thereafter		1,062
	$	6,080