Intangible Assets

3 Months Ended

Dec. 31, 2016

5.Intangible Assets

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


					September 30, 2016				December 31, 2016
					Gross				Gross
	Estimated				Carrying		Accumulated		Carrying		Accumulated
(in thousands of dollars)	useful lives				Amount		Amortization		Amount		Amortization
Trade names	Indefinite				$	63,245	$	—	$	62,474	$	—
Intellectual property			20	years		10,102		—		10,026		528
Contracts	15	-	20	years		127,520		76,029		124,920		75,067
Customer relationships	5	-	20	years		227,909		67,493		225,339		70,522
Trade names			20	years		66,755		39,744		66,755		40,579
Patents and patented technologies	6	-	19	years		5,401		2,875		5,401		2,931
Other	5	-	17	years		7,035		2,664		7,109		2,783
					$	507,967	$	188,805	$	502,024	$	192,410

The above table includes preliminary amounts for the intangible assets acquired in 2016 because the process of identifying and valuing those assets has not been completed. Total amortization expense related to intangible assets was approximately $4.6 million and $6.3 million for the December 2015 and 2016 quarters, respectively.

Total estimated annual amortization expense for 2017 through 2022 is shown in the following table; however, the amounts will change once the intangible assets for the 2016 acquisitions are identified and valuations are finalized.


Year ending September 30:	(in thousands)
2017	$	24,356
2018		24,598
2019		23,575
2020		19,471
2021		19,430
2022		19,216