Summary of Cash, Cash Equivalents and Marketable Securities Available for Sale (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013
Cash and Cash Equivalents
Cash, cash equivalents and marketable securities [Line Items]
Amortized Cost	$ 105,075	$ 83,178
Gross Unrealized Gains	0	0
Fair Value	105,075	83,178
Cash and Cash Equivalents | Cash
Cash, cash equivalents and marketable securities [Line Items]
Amortized Cost	94,749	82,493
Gross Unrealized Gains	0	0
Fair Value	94,749	82,493
Cash and Cash Equivalents | Money market funds
Cash, cash equivalents and marketable securities [Line Items]
Amortized Cost	439	439
Gross Unrealized Gains	0	0
Fair Value	439	439
Cash and Cash Equivalents | Non-U.S. money market funds
Cash, cash equivalents and marketable securities [Line Items]
Amortized Cost	9,887	246
Gross Unrealized Gains	0	0
Fair Value	9,887	246
Long-term Marketable Securities | Marketable equity securities
Cash, cash equivalents and marketable securities [Line Items]
Amortized Cost	7,220	6,006
Gross Unrealized Gains	1,531	1,101
Fair Value	$ 8,751	$ 7,107