Investments - Amortized Cost, Unrealized Holding Gains (Losses) and Fair Value of Available-for-Sale Securities (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Sep. 30, 2013
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 17,325	$ 42,522
Unrealized Gains	112	184
Unrealized Losses	(58)	(97)
Fair Value	17,379	42,609
Municipal bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	1,558	3,049
Unrealized Gains	9	15
Unrealized Losses	(3)	(5)
Fair Value	1,564	3,059
Corporate bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	1,835	4,896
Unrealized Gains	12	17
Unrealized Losses	(2)	(6)
Fair Value	1,845	4,907
U.S. government and government agency obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	2,846	22,889
Unrealized Gains	21	28
Unrealized Losses	(3)	(27)
Fair Value	2,864	22,890
Mortgage-backed securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	5,096	8,149
Unrealized Gains	56	118
Unrealized Losses	(46)	(51)
Fair Value	5,106	8,216
Asset-backed securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	5,990	3,539
Unrealized Gains	14	6
Unrealized Losses	(4)	(8)
Fair Value	$ 6,000	$ 3,537