Investments - Amortized Cost, Unrealized Holding Gains (Losses) and Fair Value of Available-for-Sale Securities (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Sep. 30, 2013
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 42,592	$ 42,522
Unrealized Gains	172	184
Unrealized Losses	(134)	(97)
Fair Value	42,630	42,609
Municipal Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	2,865	3,049
Unrealized Gains	17	15
Unrealized Losses	(5)	(5)
Fair Value	2,877	3,059
Corporate Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	4,657	4,896
Unrealized Gains	24	17
Unrealized Losses	(20)	(6)
Fair Value	4,661	4,907
U.S. government and government agency obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	21,783	22,889
Unrealized Gains	22	28
Unrealized Losses	(38)	(27)
Fair Value	21,767	22,890
Mortgage-backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	7,939	8,149
Unrealized Gains	101	118
Unrealized Losses	(63)	(51)
Fair Value	7,977	8,216
Asset-backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	5,348	3,539
Unrealized Gains	8	6
Unrealized Losses	(8)	(8)
Fair Value	$ 5,348	$ 3,537