5. Software and Other Intangible Assets

At December 31, 2012, software net book value totaled $129.3 million, net of $69.4 million of accumulated amortization. Included in this amount is software marketed for external sale of $100.4 million. The remaining software net book value of $28.9 million is comprised of various software that has been acquired or developed for internal use.

At December 31, 2011, software net book value totaled $22.6 million, net of $54.7 million of accumulated amortization. Included in this amount is software marketed for external sale of $10.3 million. The remaining software net book value of $12.3 million is comprised of various software that has been acquired or developed for internal use.

Amortization of acquired software marketed for external sale is computed using the greater of the ratio of current revenues to total current and anticipated revenues expected to be derived from the software or the straight-line method over an estimated useful life of generally three to six years. Software for resale amortization expense recorded during the years ended December 31, 2012, 2011 and 2010 totaled $13.8 million, $6.3 million, and $6.0 million, respectively. These software amortization expense amounts are reflected in cost of software license fees in the consolidated statements of income. Amortization of software for internal use recorded during the years ended December 31, 2012, 2011 and 2010 totaled $11.6 million, $8.1 million, and $7.4 million, respectively. These software amortization expense amounts are reflected in depreciation and amortization in the consolidated statements of income.

The carrying amount and accumulated amortization of the Company’s other intangible assets that were subject to amortization at each balance sheet date are as follows (in thousands):


	December 31, 2012							December 31, 2011
	Gross Carrying Amount		Accumulated Amortization			Net Balance		Gross Carrying Amount		Accumulated Amortization			Net Balance
Customer relationships	$	157,364	$	(33,727	)	$	123,637	$	40,298	$	(23,392	)	$	16,906
Purchased contracts		10,823		(10,549	)		274		10,750		(10,023	)		727
Trademarks and tradenames		5,830		(2,096	)		3,734		1,291		(585	)		706
Covenant not to compete		442		(187	)		255		80		(76	)		4

	$	174,459	$	(46,559	)	$	127,900	$	52,419	$	(34,076	)	$	18,343

Other intangible assets amortization expense recorded during the years ended December 31, 2012, 2011 and 2010 totaled $12.1 million, $6.4 million, and $6.3 million, respectively. Based on capitalized intangible assets at December 31, 2012, and assuming no impairment of these intangible assets, estimated amortization expense amounts in future fiscal years are as follows (in thousands):


Fiscal Year Ending December 31,	Software Amortization		Other Intangible Assets Amortization
2013	$	23,760	$	13,388
2014		21,651		11,589
2015		17,584		8,247
2016		14,928		7,775
2017		12,745		7,234
Thereafter		38,646		79,667

Total	$	129,314	$	127,900