Property, Plant, and Equipment, Net (Narrative) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011
Land and Land Improvements	$ 57,562	$ 27,794
Construction in progress	81,428	27,643
Payments to Acquire Property, Plant, and Equipment	141,600	64,900	48,255
Second Campus Rockford Illinois [Member]
Land and Land Improvements	1,809
Construction in progress	15,691
Capitalized interest	444
New Campus Fort Collins Colorado [Member]
Land and Land Improvements	9,302
Construction in progress	10,514
Capitalized interest	394
Building Site Niles Illinois [Member]
Land and Land Improvements	13,535
Construction in progress	12,067
Payments to Acquire Property, Plant, and Equipment	$ 25,602