Immaterial Restatement - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	6 Months Ended
Mar. 31, 2013
Increase in the carrying value of strategic investments	$ 1.2

The net cash inflow or outflow for the increase (decrease) associated with investments (not to include restricted cash) that are pledged or subject to withdrawal restrictions.

No definition available.

Name:	us-gaap_IncreaseDecreaseOfRestrictedInvestments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration