Selected Quarterly Financial Data (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended																12 Months Ended
	Sep. 30, 2014		Jun. 30, 2014		Mar. 31, 2014		Dec. 31, 2013		Sep. 30, 2013		Jun. 30, 2013		Mar. 31, 2013		Dec. 31, 2012		Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2012
Quarterly Financial Information Disclosure [Abstract]
Total revenue	$ 545,905		$ 354,671		$ 270,021		$ 293,170		$ 438,334		$ 314,439		$ 287,902		$ 246,902		$ 1,463,767	$ 1,287,577	$ 1,005,677
Gross profit	87,813	[1]	68,804	[1]	52,172	[1]	54,670	[1]	80,046	[1]	54,115	[1]	43,885	[1]	36,084	[1]	263,459	214,130	105,088
Operating income (loss)	23,452		15,088		5,617		11,532		22,079		8,472		311		(3,601)		55,689	27,261	(62,058)
Income (loss) from continuing operations	60,288	[2]	(13,193)	[2]	(8,224)	[2]	(3,948)	[2]	11,328	[2]	(5,442)	[2]	(19,111)	[2]	(18,939)	[2]	34,923	(32,164)	(135,623)
Basic earnings (loss) per share from continuing operations	$ 2.28		$ (0.50)		$ (0.32)		$ (0.16)		$ 0.46		$ (0.22)		$ (0.78)		$ (0.78)		$ 1.35	$ (1.30)	$ (7.34)
Diluted earnings (loss) per share from continuing operations	$ 1.90		$ (0.50)		$ (0.32)		$ (0.16)		$ 0.36		$ (0.22)		$ (0.78)		$ (0.78)		$ 1.10	$ (1.30)	$ (7.34)
Loss on extinguishment of debt	0		(19,764)		(153)		0		(998)		0		(3,638)		0		(19,917)	(4,636)	(45,097)
Inventory impairments and option contract abandonments	$ 5,386		$ 2,010		$ 880		$ 31		$ 404		$ 0		$ 2,025		$ 204		$ 8,307	$ 2,633	$ 12,210

[1] (a)Gross profit in fiscal 2014 and 2013 includes inventory impairment and option contract abandonments as follows:(In thousands) Fiscal 2014 Fiscal 20131st Quarter $31 $2042nd Quarter 880 2,0253rd Quarter 2,010 —4th Quarter 5,386 404 $8,307 $2,633

[2] Net (loss) income from continuing operations in fiscal 2014 and 2013 includes loss on extinguishment of debt (as follows). (In thousands) Fiscal 2014 Fiscal 20131st Quarter $— $—2nd Quarter (153) (3,638)3rd Quarter (19,764) —4th Quarter — (998) $(19,917) $(4,636)