Property, Plant, and Equipment, Net (Narrative) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Sep. 30, 2013
Construction in progress	$ 97,754	$ 81,428
Second Campus Rockford Illinois [Member]
Construction in progress	27,803	15,691
Capitalized interest	737	444
New Campus Fort Collins Colorado [Member]
Construction in progress	14,651	10,514
Capitalized interest	532	394
Building Site Niles Illinois [Member]
Construction in progress	15,322	12,067
Capitalized interest	$ 346	$ 0

Amount of structure or a modification to a structure under construction. Includes recently completed structures or modifications to structures that have not been placed into service.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 360

-SubTopic 10

-Section 50

-Paragraph 1

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6391035&loc=d3e2868-110229

Name:	us-gaap_ConstructionInProgressGross
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant