8. Intangible Assets

Intangible assets consist principally of acquired patents and technology, customer lists and relationships, licenses and trademarks. The Company recorded amortization expense of $0.6 million and $0.8 million for the three months ended March 31, 2017 and 2016, respectively. The Company recorded amortization expense of $1.3 million and $1.2 million for the six months ended March 31, 2017 and 2016, respectively.

Intangible assets consisted of the following:

	March 31, 2017
(Dollars in thousands)	Weighted Average Original Life (Years)		Gross Carrying Amount		Accumulated Amortization			Net
Definite-lived intangible assets:
Customer lists and relationships		8.9	$	17,187	$	(6,842	)	$	10,345
Core technology		8.0		530		(530	)		—
Developed technology		11.8		9,077		(1,012	)		8,065
Non-compete		5.0		230		(81	)		149
Patents and other		16.5		2,321		(1,349	)		972
Subtotal				29,345		(9,814	)		19,531
Unamortized intangible assets:
In-process research and development				945		—			945
Trademarks and trade names				642		—			642
Total			$	30,932	$	(9,814	)	$	21,118

	September 30, 2016
(Dollars in thousands)	Weighted Average Original Life (Years)		Gross Carrying Amount		Accumulated Amortization			Net
Definite-lived intangible assets:
Customer lists and relationships		8.9	$	17,692	$	(6,123	)	$	11,569
Core technology		8.0		530		(530	)		—
Developed technology		11.8		8,724		(618	)		8,106
Non-compete		5.0		230		(58	)		172
Patents and other		16.5		2,321		(1,275	)		1,046
Subtotal				29,497		(8,604	)		20,893
Unamortized intangible assets:
In-process research and development				987		—			987
Trademarks and trade names				645		—			645
Total			$	31,129	$	(8,604	)	$	22,525

Based on the intangible assets in service as of March 31, 2017, excluding any possible future amortization associated with acquired in-process research and development (“IPR&D”), which has not met technological feasibility as of March 31, 2017, estimated amortization expense for the remainder of fiscal 2017 and each of the next five fiscal years is as follows:

(Dollars in thousands)
Remainder of 2017	$	1,278
2018		2,510
2019		2,510
2020		2,335
2021		2,196
2022		2,156

Future amortization amounts presented above are estimates. Actual future amortization expense may be different as a result of future acquisitions, impairments, completion or abandonment of IPR&D intangible assets, changes in amortization periods, or other factors.

The Company defines IPR&D as the value of technology acquired for which the related projects have substance and are incomplete. IPR&D acquired in a business acquisition is recognized at fair value and requires the IPR&D to be capitalized as an indefinite-lived intangible asset until completion of the IPR&D project or abandonment. Upon completion of the development project (generally when regulatory approval to market the product is obtained), an impairment assessment is performed prior to amortizing the asset over its estimated useful life. If the IPR&D projects are abandoned, the related IPR&D assets would be written off.