(7)OTHER INTANGIBLE ASSETS

Other intangible assets which are included in Other long-term assets in the accompanying Consolidated Balance Sheets consisted of the following (in thousands):


					Acquisitions		Effect of
	December 31,				and		Foreign		December 31,
	2014		Amortization		Adjustments		Currency		2015
Customer relationships, gross	$	63,914	$	—	$	(2,982)	$	1,325	$	62,257
Customer relationships - accumulated amortization		(20,326)		(7,401)		—		(2,453)		(30,180)
Other intangible assets, gross		13,113		—		986		(349)		13,750
Other intangible assets - accumulated amortization		(6,509)		(2,345)		—		99		(8,755)
Trade name - indefinite life		9,713		—		5,544		(1,114)		14,143
Other intangible assets, net	$	59,905	$	(9,746)	$	3,548	$	(2,492)	$	51,215


							Effect of
	December 31,						Foreign		December 31,
	2013		Amortization		Acquisitions		Currency		2014
Customer relationships, gross	$	50,830	$	—	$	14,115	$	(1,031)	$	63,914
Customer relationships - accumulated amortization		(13,547)		(6,779)		—		—		(20,326)
Other intangible assets, gross		11,634		—		1,607		(128)		13,113
Other intangible assets - accumulated amortization		(3,818)		(2,691)		—		—		(6,509)
Trade name - indefinite life		9,713		—		—		—		9,713
Other intangible assets, net	$	54,812	$	(9,470)	$	15,722	$	(1,159)	$	59,905

The adjustments recorded during 2015 relate to the finalization of the purchase price valuation for the rogenSi acquisition which resulted in an increase to the trade name and decrease in the customer relationships intangible assets. See Note 2 for further information.

Customer relationships are being amortized over the remaining weighted average useful life of 4.7 years and other intangible assets are being amortized over the remaining weighted average useful life of 2.4 years. Amortization expense related to intangible assets was $9.7 million, $9.6 million and $7.2 million for the years ended December 31, 2015, 2014 and 2013, respectively.

Expected future amortization of other intangible assets as of December 31, 2015 is as follows (in thousands):


2016	$	9,648
2017		7,900
2018		5,987
2019		5,495
2020		3,263
Thereafter		4,779
Total	$	37,072

In connection with the reorganization of the CSS segment an interim impairment analysis was completed during the second quarter of 2013. The indefinite-lived intangible asset evaluated for impairment consisted of the PRG trade name. The Company calculated the fair value of the trade name using a relief from royalty method based on forecasted revenues sold under the trade name using significant inputs not observable in the market (Level 3 inputs). The valuation assumptions included an estimated royalty rate of 6.0%, a discount rate specific to the trade name of 38.0% and a perpetuity growth rate of 7.0%. Based on the calculated fair value of $5.3 million, the Company recorded impairment expense of $1.1 million in the three months ended June 30, 2013. The Company reevaluated the PRG trade name for impairment as of December 31, 2013. The Company used the same method to fair value the PRG trade name and similar inputs described above. The forecasted revenues used to fair value the PRG trade name changed resulting in a fair value of $5.7 million. This fair value was approximately 7% higher than the book value of $5.3 million. As a result, the Company continues to evaluate the PRG trade name for impairment.

Definite-lived long-lived assets consisted of fixed assets and an intangible asset related to the PRG customer relationships. The Company determined that the undiscounted future cash flows would be sufficient to cover the net book value of all definite-lived long-lived assets upon reorganization of the Customer Strategy Services segment and as of December 31, 2013.