(7) Intangibles

Acquired other intangible assets consisted of the following at June 30, 2014 and December 31, 2013 (dollars in thousands):

	June 30, 2014				December 31, 2013
	Gross Carrying Amount		Accumulated Amortization		Gross Carrying Amount		Accumulated Amortization		Useful Lives (Years)
Trade names	$	8,400	$	—	$	8,400	$	—	—
Customer-related intangibles	27,851		10,035		27,851		8,923		13.1
Proprietary software	21,501		19,275		21,501		17,921		6.4
Trading rights	340		—		243		—		—
Other	50		—		50		—		—
Total	$	58,142	$	29,310	$	58,045	$	26,844

At June 30, 2014, indefinite-lived intangibles not subject to amortization amounted to $8.8 million, of which $8.4 million related to the POSIT trade name.

Amortization expense for definite-lived intangibles was $1.2 million and $2.4 million for the three months and six months ended June 30, 2014, respectively, compared with $1.0 and $2.1 million in the respective prior-year periods. These amounts are included in other general and administrative expense in the Condensed Consolidated Statements of Income.

During the six months ended June 30, 2014, no intangibles were deemed impaired, and accordingly, no adjustment was required.