(7) Goodwill and Intangible Assets

Changes in goodwill by operating segment for the three months ended March 31, 2015 are as follows (in thousands):

	Supply Chain Management		IT, Energy and Management Consulting		Aviation		Total
Balance as of December 31, 2014	$	61,169	$	30,883	$	-	$	92,052
Increase from the Aviation Acquisition		-		-	$	101,720	$	101,720
Balance as of March 31, 2015	$	61,169	$	30,883	$	101,720	$	193,772

Intangible assets consist of the value of contract-related assets, acquired technologies and trade names. Amortization expense was approximately $3.6 million and $2.5 million for the three-month periods ended March 31, 2015 and 2014, respectively.

Intangible assets were comprised of the following (in thousands):

	Cost		Accumulated Amortization			Accumulated Impairment Loss			Net Intangible Assets
March 31, 2015
Contract and customer-related	$	179,004	$	(36,796	)	$	(1,025	)	$	141,183
Acquired technologies		12,400		(4,306	)		-			8,094
Trade names – amortizable		17,600		(5,108	)		-			12,492
Total	$	209,004	$	(46,210	)	$	(1,025	)	$	161,769

December 31, 2014
Contract and customer-related	$	93,304	$	(33,840	)	$	(1,025	)	$	58,439
Acquired technologies		12,400		(4,024	)		-			8,376
Trade names – amortizable		10,100		(4,706	)		-			5,394
Total	$	115,804	$	(42,570	)	$	(1,025	)	$	72,209