The following table summarizes the changes in the carrying amount of goodwill (in millions):

	Americas			EMEA			Asia Pacific		Immaterial Product Category Operating Segments			Total
Balance at January 1, 2018
Goodwill	$	7,724.8		$	1,379.8		$	500.5	$	1,741.0		$	11,346.1
Accumulated impairment losses		-			-			-		(677.7	)		(677.7	)
		7,724.8			1,379.8			500.5		1,063.3			10,668.4
Currency translation		(12.4	)		(57.6	)		6.7		(34.8	)		(98.1	)
Impairment		-			(567.0	)		-		(408.9	)		(975.9	)
Balance at December 31, 2018
Goodwill		7,712.4			1,322.2			507.2		1,706.2			11,248.0
Accumulated impairment losses		-			(567.0	)		-		(1,086.6	)		(1,653.6	)
		7,712.4			755.2			507.2		619.6			9,594.4
Other acquisitions		-			-			-		25.0			25.0
Currency translation		(12.6	)		(5.4	)		0.2		(1.9	)		(19.7	)
Balance at December 31, 2019
Goodwill		7,699.8			1,316.8			507.4		1,729.3			11,253.3
Accumulated impairment losses		-			(567.0	)		-		(1,086.6	)		(1,653.6	)
	$	7,699.8		$	749.8		$	507.4	$	642.7		$	9,599.7

We have five reporting units with goodwill assigned to them. We perform our annual test of goodwill impairment in the fourth quarter of every year. In 2019, we performed a qualitative test on our Americas and Asia Pacific reporting units and concluded it was more likely than not the fair value of these reporting units exceeded their carrying value. We estimated the fair value of our EMEA, Dental and CMF reporting units using the income and market approaches. The estimated fair value of our EMEA and Dental reporting units only exceeded their carrying values by less than 5 percent. The estimated fair value of our CMF reporting unit exceeded its carrying value by more than 25 percent.

We will continue to monitor the fair value of our EMEA and Dental reporting units as well as our other three reporting units in our interim and annual reporting periods. If our estimated cash flows for these reporting units decrease, we may have to record impairment charges in the future. Factors that could result in our cash flows being lower than our current estimates include: 1) decreased revenues caused by unforeseen changes in the healthcare market, or our inability to generate new product revenue from our research and development activities, and 2) our inability to achieve the estimated operating margins in our forecasts due to unforeseen factors. Additionally, changes in the broader economic environment could cause changes to our estimated discount rates, foreign currency exchange rates used to translate cash flows and comparable company valuation indicators, which may impact our estimated fair values.

As indicated in Note 18, our operating segments may change in 2020 which, under the applicable accounting rules, could cause us to change our reporting units to which goodwill is assigned and/or could cause the assets and related cash flows assigned to a reporting unit to change. A change in reporting units may lead us to perform interim impairment tests on the new reporting units. We may have long-lived assets that currently have a carrying value that is greater than their fair value, but are not impaired because the impairment test for long-lived assets compares the carrying value to undiscounted cash flows. If the carrying value of assets that are reallocated to a new reporting unit is greater than their estimated fair value (as measured by their discounted cash flows), we may need to record an impairment charge with respect to that reporting unit.

During the year ended December 31, 2018, we recorded goodwill impairment charges related to our Spine reporting unit, our EMEA reporting unit and an insignificant reporting unit of $401.2 million, $567.0 million and $7.7 million, respectively. During the year ended December 31, 2017, we recorded goodwill impairment charges related to our Office Based Technologies and Spine reporting units of $32.7 million and $272.0 million, respectively.

For more information on how the fair values of these reporting units were determined in the prior periods and the factors that led to impairment, please see our Annual Reports on Form 10-K for the years ended December 31, 2018 and 2017.

	Technology			Intellectual Property Rights			Trademarks and Trade Names			Customer Relationships			IPR&D		Other			Total
As of December 31, 2019:
Intangible assets subject to amortization:
Gross carrying amount	$	3,634.0		$	378.3		$	659.9		$	5,375.0		$	-	$	165.4		$	10,212.6
Accumulated amortization		(1,487.6	)		(191.9	)		(207.6	)		(1,489.4	)		-		(95.3	)		(3,471.8	)
Intangible assets not subject to amortization:
Gross carrying amount		-			-			454.9			-			61.9		-			516.8
Total identifiable intangible assets	$	2,146.4		$	186.4		$	907.2		$	3,885.6		$	61.9	$	70.1		$	7,257.6
As of December 31, 2018:
Intangible assets subject to amortization:
Gross carrying amount	$	3,638.5		$	180.7		$	664.2		$	5,384.4		$	-	$	128.3		$	9,996.1
Accumulated amortization		(1,282.7	)		(177.6	)		(169.3	)		(1,194.5	)		-		(80.0	)		(2,904.1	)
Intangible assets not subject to amortization:
Gross carrying amount		-			-			457.1			-			135.5		-			592.6
Total identifiable intangible assets	$	2,355.8		$	3.1		$	952.0		$	4,189.9		$	135.5	$	48.3		$	7,684.6

In 2019, we entered into an agreement and paid $192.5 million to buy out certain licensing arrangements from an unrelated third party. This new agreement and the related payment replaced the variable royalty payments that otherwise would have been due under the terms of previous licensing arrangements through 2029. Under the new agreement, we maintain the rights to the counterparty’s intellectual property provided under the previous licensing arrangements. The $192.5 million payment was recognized as an intangible asset and will be amortized through 2029, which represents the useful life of the intellectual property.

We recognized intangible asset impairment charges of $70.1 million, $3.8 million and $26.8 million in the years ended December 31, 2019, 2018 and 2017, respectively, in “Goodwill and intangible asset impairment” on our consolidated statements of earnings. The impairment charges were primarily related to the abandonment of IPR&D projects that were recognized as part of the Biomet merger purchase accounting.

Estimated annual amortization expense based upon intangible assets recognized as of December 31, 2019 for the years ending December 31, 2020 through 2024 is (in millions):