5.	Other Assets

Other assets consist of the following:

December 31,	2013			2012

Patents, at cost	$	5,401		$	5,021
Accumulated amortization		(3,075	)		(2,826	)
Deposits on capital items		14,091			3,934
Software development costs, at cost		2,057			2,057
Accumulated amortization		(969	)		(498	)
Investment in equity securities		259			1,331
Other		700			549
	$	18,464		$	9,568

The capitalized cost of patents is amortized using the straight-line method over their useful lives. The cost of patent amortization was $0.2 million in each 2013, 2012, and 2011. The estimated annual patent amortization cost for each of the next five years is $0.2 million. Costs incurred to maintain existing patents are charged to expense in the year incurred.

Software development costs were incurred to develop and implement an integrated ERP system prior to the time the system became operational. These costs are being amortized using the straight line method over a period of sixty months. Costs incurred subsequent to the system becoming operational are being expensed. The cost of software development cost amortization was $0.5 million, $0.4 million, and $0.1 million in 2013, 2012, and 2011, respectively.

One investment in equity securities accounted for on the equity method of accounting consists of a 29% interest in a crossbow manufacturer. This investment was evaluated for impairment as of December 31, 2013 and it was determined that the investment has been impaired and that the impairment is other than temporary. As a result, the Company recognized an impairment loss of $0.9 million in 2013.

Another investment in equity securities accounted for on the equity method of accounting was evaluated for impairment as of December 31, 2012 and it was determined that the investment had been impaired and that the impairment was other than temporary. As a result, the Company recognized an impairment loss of $1.1 million in 2012.