Fair Value Measurements and Marketable Securities - Schedule of Unrealized Gains and Losses Related to Available-for-Sale Securities (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Jun. 30, 2013
Schedule of Available-for-sale Securities [Line Items]
Gross Amortized Cost	$ 81,183	$ 80,948
Gross Unrealized Gains	3	6
Gross Unrealized Losses	23	22
Estimated Fair Value	81,163	80,932
U.S. municipal securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Amortized Cost	18,250	25,538
Gross Unrealized Gains	3	6
Estimated Fair Value	18,253	25,544
Certificates of deposit [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Amortized Cost	23,818	16,945
Gross Unrealized Losses	23	22
Estimated Fair Value	23,795	16,923
Money market funds [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Amortized Cost	39,115	38,465
Estimated Fair Value	$ 39,115	$ 38,465