Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2011	Jun. 30, 2010
Liabilities:
Fair value liability	$ 4,854
Fair Value, Measurements, Recurring
Assets:
Fair value assets	156,038
Fair Value, Measurements, Recurring | U.S. Treasury bills and money market funds
Assets:
Fair value assets	153,038
Fair Value, Measurements, Recurring | Restricted cash
Assets:
Fair value assets	3,000
Fair Value, Measurements, Recurring | Contingent consideration
Liabilities:
Fair value liability	4,854
Fair Value, Inputs, Level 1 | Fair Value, Measurements, Recurring
Assets:
Fair value assets	156,038
Fair Value, Inputs, Level 1 | Fair Value, Measurements, Recurring | U.S. Treasury bills and money market funds
Assets:
Fair value assets	153,038
Fair Value, Inputs, Level 1 | Fair Value, Measurements, Recurring | Restricted cash
Assets:
Fair value assets	3,000
Fair Value, Inputs, Level 3 | Fair Value, Measurements, Recurring | Contingent consideration
Liabilities:
Fair value liability	$ 4,854