Intangible Assets (Tables)

6 Months Ended

Mar. 31, 2016

Intangible Assets

Schedule of gross carrying amounts and accumulated amortization of intangible assets

					September 30, 2015				March 31, 2016
					Gross				Gross
	Estimated				Carrying		Accumulated		Carrying		Accumulated
(in thousands of dollars)	useful lives				Amount		Amortization		Amount		Amortization
Trade names	Indefinite				$	15,300	$	—	$	22,135	$	—
Intellectual property	Indefinite					—		—		10,650		—
CCP contracts	15	-	20	years		112,300		69,875		112,300		72,717
Customer relationships	5	-	17	years		109,078		57,844		117,849		61,955
Trade names	5	-	20	years		66,960		36,554		66,960		38,245
Patents and patented technologies	5	-	19	years		14,526		12,574		15,021		12,515
Other	5	-	17	years		4,585		2,184		4,685		2,406
					$	322,749	$	179,031	$	349,600	$	187,838

Schedule of total currently estimated annual amortization expense

Year ending September 30, :	(in thousands)
2016	$	18,759
2017		17,875
2018		17,830
2019		16,808
2020		12,574
2021		12,514