Fair Value Measurements (Assets and Liabilities Carried at Fair Value Measured on Recurring Basis) (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Jun. 30, 2012
Assets:
Cash equivalents	$ 7,187	$ 4,292
Marketable securities
Marketable securities	16,445	14,238
Corporate bonds
Marketable securities
Marketable securities	6,060	5,950
Commercial paper
Marketable securities
Marketable securities	2,698	3,046
Certificates of deposit
Marketable securities
Marketable securities	500	950
Quoted prices in active markets (Level 1)
Assets:
Cash equivalents	7,036	4,042
Marketable securities
Marketable securities	11,312	7,726
Quoted prices in active markets (Level 1) | Corporate bonds
Marketable securities
Marketable securities	4,276	3,684
Significant other observable inputs (Level 2)
Assets:
Cash equivalents	151	250
Marketable securities
Marketable securities	5,133	6,512
Significant other observable inputs (Level 2) | Corporate bonds
Marketable securities
Marketable securities	1,784	2,266
Significant other observable inputs (Level 2) | Commercial paper
Marketable securities
Marketable securities	2,698	3,046
Significant other observable inputs (Level 2) | Certificates of deposit
Marketable securities
Marketable securities	500	950
Significant unobservable inputs (Level 3)
Assets:
Cash equivalents
Marketable securities
Marketable securities
Significant unobservable inputs (Level 3) | Corporate bonds
Marketable securities
Marketable securities
Significant unobservable inputs (Level 3) | Commercial paper
Marketable securities
Marketable securities
Significant unobservable inputs (Level 3) | Certificates of deposit
Marketable securities
Marketable securities