(6)	Goodwill and Intangible Assets

The change in the carrying amount of goodwill for the nine months ended September 30, 2018, is as follows:

Balance as of December 31, 2017	$	43,626
Acquisition of business (see Note 4)		228,504
Translation effect		(706	)
Balance as of September 30, 2018	$	271,424

As of September 30, 2018, goodwill of $228,747 relates to the FDF segment. The remaining goodwill relates to the API segment.

Acquired intangible assets, which are amortized, consist of the following:

		As of September 30, 2018
	Amortization Period	Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount
Internal-use software	3 - 7 years	$	7,034	$	(2,636	)	$	4,398
Technology-based intangibles	20 years		3,519		(1,496	)		2,023
Customer-related intangibles	10 - 15 years		187,942		(2,404	)		185,538
		$	198,495	$	(6,536	)	$	191,959

		As of December 31, 2017
	Amortization Period	Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount
Internal-use software	3 - 7 years	$	7,074	$	(1,810	)	$	5,264
Technology-based intangibles	20 years		3,646		(1,413	)		2,233
Customer-related intangibles	10 - 15 years		7,608		(1,237	)		6,371
		$	18,328	$	(4,460	)	$	13,868

The change in the gross carrying amount in 2018 is mainly due to the provisional recognition of customer-related intangibles of $180,000 due to the acquisition of Halo Pharma in September 2018 and the impact of foreign currency translation. The change in the gross carrying amount in 2017 is mainly due to foreign currency translation and additions.

Amortization expense was $1,134 and $2,157 for the three and nine months ended September 30, 2018, respectively. This includes amortization expense of $627 related to the acquisition of Halo Pharma. Amortization expense was $477 and $1,375 for the three and nine months ended September 30, 2017, respectively.

Amortization expense related to intangible assets is expected to be approximately $5,043 for 2018, $14,053 for 2019, $14,037 for 2020, $14,031 for 2021, and $13,610 for 2022.