Intangible Assets

12 Months Ended

Mar. 31, 2018

Goodwill and Intangible Assets Disclosure [Abstract]

Intangible assets at March 31, 2018 and 2017 consisted of the following (in thousands):



	2018							2017
	Gross Amount		Accumulated Amortization			Net Book Value		Gross Amount		Accumulated Amortization			Net Book Value		Estimated Useful Life
Licenses	$	4,322	$	(4,322	)	$	—	$	4,422	$	(4,134	)	$	288	7
Core technology and know-how	8,703		(5,473		)	3,230		4,806		(4,793		)	13		5-10
Intangible assets	$	13,025	$	(9,795	)	$	3,230	$	9,228	$	(8,927	)	$	301

The Company recorded intangible amortization expense of $0.5 million, $0.6 million, and $0.6 million for the fiscal years ended March 31, 2018, 2017, and 2016, respectively.

Expected future amortization expense related to intangible assets is as follows (in thousands):



Fiscal years ending March 31,	Total
2019	340
2020	340
2021	340
2022	340
2023	340
Thereafter	1,530
Total	$	3,230

The geographic composition of intangible assets is as follows (in thousands):



	March 31,
	2018		2017
Intangible assets by geography:
U.S.	$	3,230	$	301
Total	$	3,230	$	301

The business segment composition of intangible assets is as follows (in thousands):



	March 31,
	2018		2017
Intangible assets by business segments:
Grid	$	3,230	$	301
Total	$	3,230	$	301