Significant Accounting Policies - Components of Cash and Cash Equivalents (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Sep. 30, 2013	Mar. 31, 2013	Sep. 30, 2012
Cash and Cash Equivalents [Line Items]
Cash on hand - Restricted	$ 1,000	$ 1,000
Total	38,213	44,282	38,594	31,593
Cash and Cash Equivalents [Member]
Cash and Cash Equivalents [Line Items]
Overnight repurchase agreements	23,791	32,103
Cash on hand - Restricted
Cash on hand - Unrestricted	14,422	12,179
Total	38,213	44,282
Other [Member]
Cash and Cash Equivalents [Line Items]
Overnight repurchase agreements
Cash on hand - Restricted	1,000	1,000
Cash on hand - Unrestricted
Total	$ 1,000	$ 1,000