Debt (Tables)

9 Months Ended

Jun. 30, 2018

Debt Disclosure [Abstract]

Long term debt instruments

The following tables present our debt instruments outstanding, contractual maturities and interest expense:

	June 30, 2018									June 30, 2017							September 30, 2017
	Gross Amount			Debt Discount and Issuance Costs			Carrying Amount			Gross Amount		Debt Discount and Issuance Costs			Carrying Amount		Gross Amount		Debt Discount and Issuance Costs			Carrying Amount
	(in thousands)
2019 Convertible Notes	$	195,000		$	(10,177	)	$	184,823		$	230,000	$	(23,721	)	$	206,279	$	195,000	$	(17,654	)	$	177,346
2019 Convertible Notes Embedded Derivative	7,491			—			7,491			5,900		—			5,900		6,591		—			6,591
2024 Convertible Notes	143,750			(39,188		)	104,562			—		—			—		143,750		(42,880		)	100,870
2025 Convertible Notes	172,500			(54,165		)	118,335			—		—			—		—		—			—
Other debt*	3,482			—			3,482			—		—			—		—		—			—
Term loan facility	—			—			—			50,000		(1,765		)	48,235		—		—			—
Total	$	522,223		$	(103,530	)	$	418,693		$	285,900	$	(25,486	)	$	260,414	$	345,341	$	(60,534	)	$	284,807
Less current portion	(205,973		)	10,177			(195,796		)	—		—			—		—		—			—
Total long-term debt	$	316,250		$	(93,353	)	$	222,897		$	285,900	$	(25,486	)	$	260,414	$	345,341	$	(60,534	)	$	284,807

* Purchase money financing; debt classified as current as collateral was destroyed. Insurance proceeds are expected to cover the entire loss.

Principal payment schedule

	Schedule of Contractual Maturities
	Total		Less Than 1 Year		1 - 3 Years		3 - 5 Years		More Than 5 Years
	(in thousands)
2019 Convertible Notes*	$	195,000	$	195,000	$	—	$	—	$	—
2024 Convertible Notes*	143,750		—		—		—		143,750
2025 Convertible Notes*	172,500		—		—		—		172,500
Other debt	3,482		3,482		—		—		—
	$	514,732	$	198,482	$	—	$	—	$	316,250

* Excludes the potential impact of embedded derivatives.

Schedule of Interest Expense

	Three Months Ended June 30,				Nine Months Ended June 30,
	2018		2017		2018		2017
	(in millions)
2019 Convertible Notes:
Contractual interest expense	$	1.1	$	1.3	$	3.2	$	3.8
Amortization of debt discount and deferred financing costs	2.5		2.8		7.5		8.3
Total interest expense	$	3.6	$	4.1	$	10.7	$	12.1
2024 Convertible Notes:
Contractual interest expense	$	1.1	$	—	$	3.1	$	—
Amortization of debt discount and deferred financing costs	1.3		—		3.8		—
Total interest expense	$	2.4	$	—	$	6.9	$	—
2025 Convertible Notes:
Contractual interest expense	$	0.5	$	—	$	0.5	$	—
Amortization of debt discount and deferred financing costs	0.8		—		0.8		—
Total interest expense	$	1.3	$	—	$	1.3	$	—