As of January 1, 2019, the Company realigned its management structure into Products, Research, and SiriusDecisions from our prior structure of Products, Research, and Project Consulting. The Company performed a qualitative assessment of goodwill for the Products and Research reporting units (as the Project Consulting reporting unit did not contain goodwill) as of January 1, 2019, which was based on the quantitative assessment that was performed as of November 30, 2018 and activity in December 2018. The Company concluded that no impairment existed at January 1, 2019 and goodwill was reassigned as of January 1, 2019 based on the relative fair values of the Products and Research reporting units. The goodwill related to the acquisition of SiriusDecisions was allocated to the SiriusDecisions segment, except for the portion of goodwill representing revenue synergies that are expected to benefit the Research segment.

A summary of goodwill by segment and the changes in the carrying amount of goodwill is shown in the following table (in thousands):

							Sirius
	Product			Research			Decisions		Total
Balance at January 1, 2018	$	2,438		$	73,731		$	—	$	76,169
Acquisitions		10,178			—			—		10,178
Translation adjustments		(98	)		(1,084	)		—		(1,182	)
Balance at December 31, 2018		12,518			72,647			—		85,165
Reassignment		(12,518	)		12,518			—		—
Acquisition		—			16,025			142,544		158,569
Translation adjustments		—			121			40		161
Balance at December 31, 2019	$	—		$	101,311		$	142,584	$	243,895

While the Company uses its best estimates and assumptions as part of the purchase price allocation process to value the assets acquired and liabilities assumed on the acquisition date, its estimates and assumptions are subject to refinement. During the measurement period, which may be up to one year from the acquisition date, the Company records adjustments to the assets acquired and liabilities assumed with a corresponding offset to goodwill to reflect additional information received about facts and circumstances which existed at the date of acquisition. The Company records adjustments to the assets acquired and liabilities assumed subsequent to the purchase price allocation period in the Company’s operating results in the period in which the adjustments are determined. During the year-ended December 31, 2019, the Company recorded measurement period adjustments of $0.8 million primarily related to deferred taxes. As of December 31, 2019, the measurement period was completed for the SiriusDecisions acquisition.

As of December 31, 2019, the Company had no accumulated goodwill impairment losses.

During the year ended December 31, 2019, $115.0 million of intangible assets were added as a result of the acquisition of SiriusDecisions. During the year ended December 31, 2018, $4.8 million and $0.6 million of intangible assets were added as a result of the acquisitions of FeedbackNow and GlimpzIt, respectively.

	December 31, 2019
	Gross				Net
	Carrying		Accumulated		Carrying
	Amount		Amortization		Amount
Amortizable intangible assets:
Customer relationships	$	109,825	$	40,169	$	69,656
Technology		16,661		7,051		9,610
Backlog		13,000		6,500		6,500
Trademarks		12,451		854		11,597
Total	$	151,937	$	54,574	$	97,363

	December 31, 2018
	Gross				Net
	Carrying		Accumulated		Carrying
	Amount		Amortization		Amount
Amortizable intangible assets:
Customer relationships	$	32,823	$	31,604	$	1,219
Technology		3,610		295		3,315
Trademarks		443		26		417
Total	$	36,876	$	31,925	$	4,951

Amortization expense related to intangible assets was approximately $22.6 million, $1.2 million, and $0.8 million during the years ended December 31, 2019, 2018 and 2017, respectively. Estimated intangible asset amortization expense for each of the five succeeding years is as follows (in thousands):