Intangible Assets (Tables)

3 Months Ended

Dec. 31, 2016

Intangible Assets

Schedule of gross carrying amounts and accumulated amortization of intangible assets

					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

Schedule of total currently estimated annual amortization expense

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