Goodwill and Other Identifiable Intangible Assets (Tables)

3 Months Ended

Mar. 31, 2018

Goodwill and Intangible Assets Disclosure [Abstract]

Carrying Amount of Goodwill by Segment

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

In millions	December 31, 2017		Foreign currency  translation/other		March 31, 2018
Water	$	2,112.9	$	25.9	$	2,138.8
Electrical	2,238.2		3.1		2,241.3
Total goodwill	$	4,351.1	$	29.0	$	4,380.1

Detail of Identifiable Intangible Assets

Identifiable intangible assets consisted of the following:

	March 31, 2018							December 31, 2017
In millions	Cost		Accumulated amortization			Net		Cost		Accumulated amortization			Net
Definite-life intangibles
Customer relationships	$	1,514.9	$	(460.5	)	$	1,054.4	$	1,513.9	$	(437.5	)	$	1,076.4
Trade names	1.5		(1.5		)	—		1.5		(1.4		)	0.1
Proprietary technology and patents	133.7		(98.4		)	35.3		131.9		(94.2		)	37.7
Total definite-life intangibles	1,650.1		(560.4		)	1,089.7		1,647.3		(533.1		)	1,114.2
Indefinite-life intangibles
Trade names	446.8		—			446.8		444.2		—			444.2
Total intangibles	$	2,096.9	$	(560.4	)	$	1,536.5	$	2,091.5	$	(533.1	)	$	1,558.4

Estimated Future Amortization Expense for Identifiable Intangible Assets

Estimated future amortization expense for identifiable intangible assets during the remainder of 2018 and the next five years is as follows:

	Q2-Q4
In millions	2018		2019		2020		2021		2022		2023
Estimated amortization expense	$	72.0	$	89.4	$	84.1	$	77.5	$	69.8	$	67.2