Intangible Assets

6 Months Ended

Mar. 31, 2014

6. Intangible Assets

The following table summarizes the gross carrying amounts and related accumulated amortization of intangible assets as of:

		September 30, 2013				March 31, 2014
(in thousands of dollars)	Estimated useful lives	Gross Carrying Amount		Accumulated Amortization		Gross Carrying Amount		Accumulated Amortization

Trade names	Indefinite	$	4,800	—		$	11,400	—

CCP contracts	15 - 20 years	106,400		$	58,699	110,590		$	61,391
Customer relationships	5 - 15 years	83,564		44,129		102,164		47,456
Trade names	5 - 20 years	67,790		30,502		67,790		32,240
Patents and patented technologies	6 - 19 years	55,099		46,954		54,869		49,561
Other	6 - 17 years	3,960		1,532		3,935		1,569
		$	321,613	$	181,816	$	350,748	$	192,217

The increase in gross carrying amount of intangible assets from September 30, 2013 to March 31, 2014 is primarily attributable to assets acquired in the acquisition transactions described in Note 3. Total amortization expense related to intangible assets was approximately $5.3 million and $5.5 million for the quarters ended March 31, 2013 and 2014, respectively, and approximately $10.2 million and $10.6 million for the six months ended March 31, 2013 and 2014, respectively. Amortization expense for fiscal 2014 is subject to finalization of the valuation efforts related to the intangible assets acquired in the 2014 transactions, as described in Note 3.

Total currently estimated annual amortization expense for 2014 through 2019 is shown in the following table, which estimates are subject to change when the fair values of the intangible assets acquired in 2014 are finalized.

Year ending September 30:	(in thousands)
2014	$	21,087
2015	17,305
2016	17,048
2017	16,169
2018	16,119
2019	15,092