9.GOODWILL

Changes to the carrying amount of goodwill by segment are as follows:



	Materials			Delivery Systems and Services			Total
(In millions)
Balance at September 30, 2015	$	150.6		$	16.4		$	167.0
Currency translation adjustment	12.0			1.1			13.1
Balance at September 30, 2016	$	162.6		$	17.5		$	180.1
Acquisition (Note 23)	5.0			—			5.0
Currency translation adjustment	(2.3		)	(0.2		)	(2.5		)
Balance at September 30, 2017	$	165.3		$	17.3		$	182.6

Goodwill is subject to impairment testing in the fourth quarter of each fiscal year and whenever events and changes in circumstances indicate that the carrying value of goodwill might not be recoverable.

We conducted impairment tests in the fourth quarter of 2017 and determined that there was no goodwill impairment. As of the fourth quarter of 2017, the fair value of each reporting unit exceeded its carrying value.