CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (USD $) In Thousands, except Share data, unless otherwise specified	Total	Common Stock	Paid in Capital	Accumulated Deficit	Accumulated Other Comprehensive Loss
Stockholders' equity at Sep. 30, 2011	$ 198,380	$ 15	$ 624,811	$ (426,446)
Stockholders' equity (shares) at Sep. 30, 2011		15,118,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(145,326)			(145,326)
Unrealized loss related to available-for-sale securities	0
Total comprehensive income	(145,326)
Tender Offer of Mandatory Convertible & TEU, Conversion of Mandatory Convertible Notes, & Conversion of TEU (debt to stock conversion) (shares)		4,969,000
Tender Offer of Mandatory Convertible & TEU, Conversion of Mandatory Convertible Notes, & Conversion of TEU (debt to stock conversion)	56,675	5	56,670
Amortization of nonvested stock option awards	2,569		2,569
Amortization of stock option awards	1,459		1,459
Tax excess from stock transactions	(85)		(85)
Shares issued under employee stock plans, net (shares)		124,000
Shares issued under employee stock plans, net	0	0	0
Common stock issued (shares)		4,400,000
Common stock issued	60,340	5	60,335
Issuance of prepaid stock purchase contracts (shares)		0
Issuance of prepaid stock purchase contracts	88,361		88,361
Common stock redeemed (shares)		(9,000)
Common stock redeemed	(126)		(126)
Stockholders' equity at Sep. 30, 2012	262,247	25	833,994	(571,772)
Stockholders' equity (shares) at Sep. 30, 2012		24,602,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(33,868)			(33,868)
Unrealized loss related to available-for-sale securities	0
Total comprehensive income	(33,868)
Tender Offer of Mandatory Convertible & TEU, Conversion of Mandatory Convertible Notes, & Conversion of TEU (debt to stock conversion) (shares)		566,000
Tender Offer of Mandatory Convertible & TEU, Conversion of Mandatory Convertible Notes, & Conversion of TEU (debt to stock conversion)	9,402		9,402
Amortization of nonvested stock option awards	1,986		1,986
Amortization of stock option awards	872		872
Exercises of stock options (shares)		1,000
Exercises of stock options	7		7
Tax excess from stock transactions	(36)		(36)
Shares issued under employee stock plans, net (shares)		83,000
Shares issued under employee stock plans, net	68	0	68
Common stock issued (shares)		0
Common stock issued	(7)	0	(7)
Common stock redeemed (shares)		(6,000)
Common stock redeemed	(121)		(121)
Stockholders' equity at Sep. 30, 2013	240,550	25	846,165	(605,640)
Stockholders' equity (shares) at Sep. 30, 2013		25,246,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	34,383			34,383
Unrealized loss related to available-for-sale securities	(1,276)				(1,276)
Total comprehensive income	33,107
Tender Offer of Mandatory Convertible & TEU, Conversion of Mandatory Convertible Notes, & Conversion of TEU (debt to stock conversion) (shares)		1,368,000
Tender Offer of Mandatory Convertible & TEU, Conversion of Mandatory Convertible Notes, & Conversion of TEU (debt to stock conversion)	2,484	2	2,482
Amortization of nonvested stock option awards	1,755		1,755
Amortization of stock option awards	832		832
Exercises of stock options (shares)		3,000
Exercises of stock options	39		39
Tax excess from stock transactions	698		698
Shares issued under employee stock plans, net (shares)		596,000
Shares issued under employee stock plans, net	103	0	103
Forfeiture of restricted stock (shares)		(16,000)
Common stock redeemed (shares)		(24,000)
Common stock redeemed	(450)		(450)
Stockholders' equity at Sep. 30, 2014	$ 279,118	$ 27	$ 851,624	$ (571,257)	$ (1,276)
Stockholders' equity (shares) at Sep. 30, 2014		27,173,000