Intangible Assets

12 Months Ended

Apr. 30, 2013

Intangible Assets

10. Intangible Assets

We record intangible assets at cost. Intangible assets consist of customer relationships, trademarks, trade names, and patents. We amortize patents and developed technology using the straight-line method over their estimated useful lives ranging from eight to 20 years. We amortize customer relationships in pro-ration to the expected yearly revenue generated from the customer lists acquired, currently estimated at 20 years.

The following table presents a summary of intangible assets for the year ended April 30, 2013 (dollars in thousands):

	April 30, 2013			April 30, 2012
Customer relationships	$	1,740		$	1,740
Patents, trademarks, and tradenames		5,264			5,222
		7,004			6,962
Less: Accumulated amortization		(3,039	)		(2,430	)
Total intangible assets, net	$	3,965		$	4,532

Amortization expense, excluding amortization of deferred financing costs, amounted to $639,000, $656,000, and $630,000 for the fiscal years ended April 30, 2013, 2012, and 2011, respectively. We expect amortization expense will be approximately $600,000 annually over each of the next five fiscal years.