Investments - Amortized Cost and Fair Value of Investments by Contractual Maturity (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013
Amortized cost
Debt securities due within one year	$ 10,712
Debt securities due within one to five years	25,080
Debt securities due within five years or more	6,673
Total	42,465
Fair value
Debt securities due within one year	10,723
Debt securities due within one to five years	25,000
Debt securities due within five years or more	6,694
Total	$ 42,417