The changes in the carrying amount of goodwill for the years ended December 31, 2018 and 2017, by reportable segment and for the “All Other” category, were as follows:

In millions
	Domestic and Canada RCS			International RCS			All Other			Total
Balance as of January 1, 2017	$	2,811.8		$	498.4		$	280.8		$	3,591.0
Goodwill acquired during year		36.9			4.9			4.7			46.5
Purchase accounting adjustments		(10.1	)		1.2			1.5			(7.4	)
Impairments during the year		-			(65.0	)		-			(65.0	)
Impairments related to disposition and held for sale (see Note 4)		-			(7.1	)		-			(7.1	)
Changes due to foreign currency fluctuations		11.6			34.4			-			46.0
Balance as of December 31, 2017		2,850.2			466.8			287.0			3,604.0
Goodwill acquired during year		32.2			-			-			32.2
Purchase accounting adjustments		(16.9	)		-			(0.7	)		(17.6	)
Impairments during the year					(72.4	)		(286.3	)		(358.7	)
Impairments related to disposition and held for sale (see Note 4)		(5.8	)		-			-			(5.8	)
Changes due to foreign currency fluctuations		(11.3	)		(20.6	)		-			(31.9	)
Balance as of December 31, 2018	$	2,848.4		$	373.8		$	-		$	3,222.2

Accumulated non-cash impairment charges by segment as of December 31, 2018 and 2017 were as follows:

In our Form 10-Q for the quarter ended September 30, 2018, we disclosed that we were in the process of completing the October 1 annual goodwill impairment assessment and that certain of our reporting units, including Domestic CRS and Latin America, were potentially at risk for impairment based on our preliminary review of our long range plan (“LRP”) which was in the process of being finalized. We were also evaluating recent declines in our stock price and market capitalization and the impact on our reconciliation of the aggregate fair values of our reporting units to our market capitalization.

We performed our annual goodwill assessment as of October 1, 2018, and we continued to update our assumptions to reflect certain business and strategic developments during the fourth quarter, which negatively impacted the estimated cash flows of certain of our reporting units and resulted in our decision to also complete an interim assessment as of December 31, 2018. The Company determined that the Domestic CRS and Latin America reporting units’ carrying values were in excess of their estimated fair values.

Factors that contributed to the estimated fair value of the reporting units being below their carrying value include:

These challenges were factored into updates to our forecasted cash-flow assumptions during the fourth quarter to reflect our current outlook and we made certain adjustments to the discount rates used to present value these forecasted cash-flows. As a result of these impairment assessments, we recognized $286.3 million of non-cash goodwill impairment charges to fully impair our Domestic CRS reporting unit. In addition, we recognized $72.4 million of non-cash goodwill impairment charges related to our Latin America reporting unit. Following the impairment, the remaining Latin America reporting unit’s goodwill is $20 million.

We performed our annual goodwill assessment, as of October 1, 2017 and evaluated the impact of prolonged declining market trends in Latin America and continued softness in the Company’s Manufacturing and Industrial regional hazardous waste business. Our estimated cash flows were updated to reflect these challenging conditions in Latin America and, as a result of the impairment assessment, we recognized a $65.0 million non-cash goodwill impairment charge. The impairment charge recognized was the amount by which the carrying value of the Latin America reporting unit exceeded its fair value.

The fair value of reporting units, used in both the annual and any interim goodwill impairment assessments are classified as Level 3 measurements within the fair value hierarchy due to significant unobservable inputs such as discount rates, projections of revenue, cost of revenue and operating expense growth rates, long-term growth rates and income tax rates. The fair value methodology is described further in Note 1 – Basis of Presentation and Summary of Significant Accounting Policies.

Current year adjustments to goodwill for certain prior year acquisitions are primarily due to the finalization of intangible asset valuations among other opening balance sheet adjustments.

At December 31, 2018 and 2017, the values of other intangible assets were as follows:

In millions
	2018						2017
	Gross Carrying Amount		Accumulated Amortization		Net Value		Gross Carrying Amount		Accumulated Amortization		Net Value
Amortizable intangibles:
Customer relationships	$	1,591.5	$	492.0	$	1,099.5	$	1,613.4	$	381.4	$	1,232.0
Covenants not-to-compete		5.1		3.2		1.9		7.9		5.9		2.0
Tradenames		3.9		1.2		2.7		6.0		1.8		4.2
Other		12.3		3.5		8.8		17.0		3.4		13.6
Indefinite lived intangibles:
Operating permits		212.5		-		212.5		222.3		-		222.3
Tradenames		312.3		-		312.3		317.4		-		317.4
Total	$	2,137.6	$	499.9	$	1,637.7	$	2,184.0	$	392.5	$	1,791.5

The changes in the carrying amount of intangible assets since January 1, 2017 were as follows:

In millions
	Total
Balance as of January 1, 2017	$	1,862.0
Intangible assets acquired during the year		28.2
Valuation adjustments for prior year acquisitions		7.9
Reclassification to assets held for sale		(2.6	)
Impairments during the year		(21.0	)
Amortization during the year		(118.4	)
Changes due to foreign currency fluctuations		35.4
Balance as of December 31, 2017		1,791.5
Intangible assets acquired during the year		34.0
Valuation adjustments for prior year acquisitions		10.2
Reclassification to assets held for sale		(14.4	)
Impairments during the year		(16.0	)
Amortization during the year		(130.3	)
Changes due to foreign currency fluctuations		(37.3	)
Balance as of December 31, 2018	$	1,637.7

Our indefinite-lived intangible assets include operating permits and certain tradenames. We have determined that our operating permits and certain tradenames have indefinite lives due to our ability to renew them with minimal additional cost, and therefore they are not amortized. We perform our annual impairment test as of October 1.

During 2018, 2017, and 2016, we recognized non-cash impairment charges of $16.0 million, $21.0 million, and $1.4 million, respectively. The non-cash impairment charges recognized during the year ended December 31, 2018 included $10.3 million related to customer relationship and permit intangibles, which were impaired as a result of actual and forecasted business declines. The remaining non-cash impairment charges incurred during the year ended December 31, 2018 and the charges in the year ended December 31, 2017 were recognized due to rationalizing certain operations across all segments and were recognized in the following reportable segments:

In millions
	2018		2017		2016
Domestic and Canada RCS	$	0.5	$	3.1	$	-
International RCS		15.5		12.1		1.4
All Other		—		5.8		-
Total Customer Relationships and Operating Permits		16.0		21.0		1.4

Our finite-lived intangible assets are amortized over their estimated useful lives using the straight-line method with each category having a weighted average remaining useful life as follows:

We evaluate the useful life of our intangible assets annually to determine whether events and circumstances warrant a revision to their remaining useful life and changes are reflected prospectively as the intangible asset is amortized over the revised remaining useful life. In the fourth quarter of 2018, the Company performed its annual assessment of the useful life of its finite-lived intangibles. The Company updated the useful life of its customer relationship intangibles as a result of analyzing recent quantitative and qualitative observations in the market and factors impacting our business. The change in estimate will be accounted for prospectively and there will be an approximately 5-10% increase to annual amortization expense going forward.

During the years ended December 31, 2018, 2017, and 2016, our aggregate intangible asset amortization expense was $130.3 million, $118.4 million, and $129.3 million, respectively.

Our estimated intangible asset amortization expense for each of the next five years (based upon foreign exchange rates at December 31, 2018) is as follows for the years ended December 31: