GOODWILL AND OTHER INTANGIBLE ASSETS

As discussed in Note 3, goodwill arises from the purchase price for acquired businesses exceeding the fair value of tangible and intangible assets acquired less assumed liabilities and noncontrolling interests. Management assesses the goodwill of each of its reporting units for impairment at least annually at the beginning of the fourth quarter and as “triggering” events occur that indicate that it is more likely than not that an impairment exists. The Company elected to bypass the optional qualitative goodwill assessment allowed by applicable accounting standards and performed a quantitative impairment test for all reporting units as this was determined to be the most effective method to assess for impairment across a large spectrum of reporting units.

The Company estimates the fair value of its reporting units primarily using a market approach, based on current trading multiples of earnings before interest, taxes, depreciation and amortization (“EBITDA”) for companies operating in businesses similar to each of the Company’s reporting units, in addition to recent available market sale transactions of comparable businesses. In certain circumstances the Company also estimates fair value utilizing a discounted cash flow analysis (i.e., an income approach) in order to validate the results of the market approach. If the estimated fair value of the reporting unit is less than its carrying value, the Company must perform additional analysis to determine if the reporting unit’s goodwill has been impaired.

As of December 31, 2018, the Company had eight reporting units for goodwill impairment testing. As of the date of the 2018 annual impairment test, the carrying value of the goodwill included in each individual reporting unit ranged from $511 million to approximately $13.3 billion. No goodwill impairment charges were recorded for the years ended December 31, 2018, 2017 and 2016 and no “triggering” events have occurred subsequent to the performance of the 2018 annual impairment test. The factors used by management in its impairment analysis are inherently subject to uncertainty. If actual results are not consistent with management’s estimates and assumptions, goodwill and other intangible assets may be overstated and a charge would need to be taken against net earnings.

The following is a rollforward of the Company’s goodwill by segment ($ in millions):



	Life Sciences			Diagnostics				Dental			Environmental & Applied Solutions			Total
Balance, January 1, 2017	$	11,610.3		$	6,903.0			$	3,215.6		$	2,098.0		$	23,826.9
Attributable to 2017 acquisitions	95.5			—				2.8			169.3			267.6
Adjustments due to finalization of purchase price allocations	(19.1		)	(39.6		)	^(a)	8.8			—			(49.9		)
Foreign currency translation and other	648.8			216.1				142.8			86.3			1,094.0
Balance, December 31, 2017	12,335.5			7,079.5				3,370.0			2,353.6			25,138.6
Attributable to 2018 acquisitions	1,212.6			—				—			62.8			1,275.4
Adjustments due to finalization of purchase price allocations	2.8			—				—			4.7			7.5
Foreign currency translation and other	(239.9		)	(153.9		)		(44.5		)	(77.2		)	(515.5		)
Balance, December 31, 2018	$	13,311.0		$	6,925.6			$	3,325.5		$	2,343.9		$	25,906.0


^(a)	This adjustment is primarily related to finalization of the Cepheid purchase price allocations.

Finite-lived intangible assets are amortized over their legal or estimated useful life. The following summarizes the gross carrying value and accumulated amortization for each major category of intangible assets as of December 31 ($ in millions):



	2018					2017
	Gross Carrying Amount		Accumulated Amortization			Gross Carrying Amount		Accumulated Amortization
Finite-lived intangibles:
Patents and technology	$	2,985.3	$	(945.2	)	$	2,363.5	$	(783.7	)
Customer relationships and other intangibles	7,302.8		(2,661.3		)	7,354.9		(2,203.6		)
Trademarks and trade names	190.7		(28.0		)	23.9		(14.0		)
Total finite-lived intangibles	10,478.8		(3,634.5		)	9,742.3		(3,001.3		)
Indefinite-lived intangibles:
Trademarks and trade names	4,828.8		—			4,926.1		—
Total intangibles	$	15,307.6	$	(3,634.5	)	$	14,668.4	$	(3,001.3	)

During 2018, the Company acquired finite-lived intangible assets, consisting primarily of technology, with a weighted average life of 18 years. During 2017, the Company acquired finite-lived intangible assets, consisting primarily of customer relationships, with a weighted average life of nine years. Refer to Note 3 for additional information on the intangible assets acquired.

Total intangible amortization expense in 2018, 2017 and 2016 was $706 million, $661 million and $583 million, respectively. Based on the intangible assets recorded as of December 31, 2018, amortization expense is estimated to be $720 million during 2019, $709 million during 2020, $694 million during 2021, $673 million during 2022 and $665 million during 2023.