Intangible assets:

12 Months Ended

Dec. 31, 2012

Intangible assets:

Intangible assets:

10. Intangible assets:

December 31, 2012	Cost		Accumulated amortization		Net book value
Patents and trademarks	$	20,192	$	1,758	$	18,434
Technology	6,961		1,901		5,060
Customer contracts	14,404		2,709		11,695
Non-compete agreement	44		18		26
	$	41,601	$	6,386	$	35,215

December 31, 2011	Cost		Accumulated amortization		Net book value
Patents and trademarks	$	19,508	$	727	$	18,781
Technology	6,380		1,122		5,258
Customer contracts	13,334		815		12,519
Non-compete agreement	37		13		24
	$	39,259	$	2,677	$	36,582

During the year ended December 31, 2012, nine months ended December 31, 2011 and the year ended March 31, 2011, amortization of $3,264, $1,806 and $592, respectively, was recognized in the statement of operations.

The expected amortization of intangible assets for fiscal 2013 to 2017 is $3,500 per year.