Goodwill and other intangible assets

Goodwill and indefinite-lived intangible assets are evaluated for impairment annually during the fourth quarter, or more frequently if an event occurs or circumstances change that would more likely than not reduce the fair value of a reporting unit or intangible asset below its carrying value. Based on the fiscal 2018 annual impairment analysis, the fair values of the Company’s reporting units exceeded their carrying amounts ranging from approximately 11% to approximately 312%. The fair value of the Boots reporting unit, within the Retail Pharmacy International division, is in excess of its carrying value by approximately 11%. The Company continues to monitor weakness in the U.K. retail market, uncertainty surrounding future NHS funding and the U.K.’s potential exit from the European Union (commonly referred to as “Brexit”), and the potential impact these and other factors may have on the fair value of the Boots reporting units in future periods. The determination of the fair value of the reporting units requires us to make significant estimates and assumptions. Although we believe our estimates of fair value are reasonable, actual financial results could differ from those estimates due to the inherent uncertainty involved in making such estimates.

Changes in the carrying amount of goodwill by reportable segment consist of the following (in millions):



	Retail Pharmacy USA		Retail Pharmacy International			Pharmaceutical Wholesale		Walgreens Boots Alliance, Inc.
Balance at August 31, 2018	$	10,483	$	3,370		$	3,061	$	16,914
Acquisitions	8		—			—		8
Disposals	—		(8		)	—		(8		)
Currency translation adjustments	—		59			54		113
Balance at February 28, 2019	$	10,491	$	3,421		$	3,115	$	17,027

The carrying amount and accumulated amortization of intangible assets consist of the following (in millions):



	February 28, 2019		August 31, 2018
Gross amortizable intangible assets
Customer relationships and loyalty card holders	$	4,421	$	4,235
Favorable lease interests and non-compete agreements	669		680
Trade names and trademarks	507		489
Purchasing and payer contracts	382		390
Total gross amortizable intangible assets	5,979		5,794

Accumulated amortization
Customer relationships and loyalty card holders	$	1,147	$	997
Favorable lease interests and non-compete agreements	386		359
Trade names and trademarks	242		206
Purchasing and payer contracts	86		78
Total accumulated amortization	1,861		1,640
Total amortizable intangible assets, net	$	4,118	$	4,154

Indefinite-lived intangible assets
Trade names and trademarks	$	5,688	$	5,557
Pharmacy licenses	2,126		2,072
Total indefinite-lived intangible assets	$	7,814	$	7,629

Total intangible assets, net	$	11,932	$	11,783

Amortization expense for intangible assets was $139 million and $273 million for the three and six months ended February 28, 2019, respectively, and $121 million and $217 million for the three and six months ended February 28, 2018, respectively.

Estimated future annual amortization expense for the next five fiscal years for intangible assets recorded at February 28, 2019 is as follows (in millions):



	2020		2021		2022		2023		2024
Estimated annual amortization expense	$	483	$	432	$	412	$	378	$	361