Note 6. Intangible Assets

Amortization of intangible assets represents the amortization of the intangible assets from the RS and CCSS acquisitions. The gross and net carrying amounts of the acquired intangible assets as of December 31, 2010 and June 30, 2011 were as follows (in thousands):


	December 31, 2010
								Estimated
			Accumulated		Net Book			Useful Life
Description	Gross Value		Amortization		Value			(in years)
CCSS:
Backlog	$	1,900	$	1,900	$	—	*		3
Customer Relationships		1,700		524	$	1,176			10
Technology		400		400	$	—			1

Total	$	4,000	$	2,824	$	1,176


RS:
Backlog	$	12,782	$	4,687	$	8,095	*		4
Technology		8,248		602		7,646			8
Covenants not-to-compete		319		49		270			4

Total	$	21,349	$	5,338	$	16,011


	June 30, 2011
								Estimated
			Accumulated		Net Book			Useful Life
Description	Gross Value		Amortization		Value			(in years)
CCSS:
Backlog	$	1,900	$	1,900	$	—	*		3
Customer Relationships		1,700		609	$	1,091			10
Technology		400		400	$	—			1

Total	$	4,000	$	2,909	$	1,091


RS:
Backlog	$	14,005	$	7,901	$	6,104	*		4
Technology		9,432		1,191		8,241			8
Covenants not-to-compete		360		94		266			4

Total	$	23,797	$	9,186	$	14,611


*		CCSS backlog was amortized over three years on an accelerated basis and RS backlog is being amortized over four years on an accelerated basis.

The related amortization expense reflected in our consolidated statements of operations for each of the three and six months ended June 30, 2010 was $0.7 million. The related amortization expense reflected in our consolidated statements of operations for the three and six months ended June 30, 2011 was $2.0 million and $3.9 million, respectively.

Estimated amortization expense for the remaining estimated useful life of the acquired intangible assets is as follows for the years ending December 31 (in thousands):


	Amortization of Intangible Assets
Years ending December 31,	CCSS		RS		Total
2011	$	85	$	3,892	$	3,977
2012	$	170		3,742		3,912
2013	$	170		1,677		1,847
2014	$	170		1,230		1,400
2015	$	170		1,191		1,361
Thereafter	$	326		2,879		3,205

Total	$	1,091	$	14,611	$	15,702