Goodwill and Other Identifiable Intangible Assets

6 Months Ended

Jun. 30, 2019

Goodwill and Intangible Assets Disclosure [Abstract]

Goodwill and Other Identifiable Intangible Assets

The changes in the carrying amount of goodwill by reportable segment were as follows:



In millions	December 31, 2018		Acquisitions		Foreign currency translation/other			June 30, 2019
Aquatic Systems	$	965.9	$	—	$	(1.1	)	$	964.8
Filtration Solutions	643.5		214.9		1.1			859.5
Flow Technologies	463.3		—		(0.1		)	463.2
Total goodwill	$	2,072.7	$	214.9	$	(0.1	)	$	2,287.5

Identifiable intangible assets consisted of the following:



	June 30, 2019							December 31, 2018
In millions	Cost		Accumulated amortization			Net		Cost		Accumulated amortization			Net
Definite-life intangibles
Customer relationships	$	422.6	$	(258.3	)	$	164.3	$	347.1	$	(247.9	)	$	99.2
Trade names	—		—			—		0.4		(0.4		)	—
Proprietary technology and patents	49.6		(34.8		)	14.8		86.2		(68.4		)	17.8
Total definite-life intangibles	472.2		(293.1		)	179.1		433.7		(316.7		)	117.0
Indefinite-life intangibles
Trade names	175.1		—			175.1		159.3		—			159.3
Total intangibles	$	647.3	$	(293.1	)	$	354.2	$	593.0	$	(316.7	)	$	276.3

Identifiable intangible asset amortization expense was $8.3 million and $9.1 million for the three months ended June 30, 2019 and 2018, respectively, and $16.5 million and $18.4 million for the six months ended June 30, 2019 and 2018, respectively.

Estimated future amortization expense for identifiable intangible assets during the remainder of 2019 and the next five years is as follows:



	Q3-Q4
In millions	2019		2020		2021		2022		2023		2024
Estimated amortization expense	$	16.0	$	27.6	$	22.5	$	15.3	$	13.0	$	12.4