Fair Value Measurements - Schedule of Assets and Liabilities Measured at Fair Value on a Non-Recurring Basis (Detail) (Investment in unconsolidated entity – Blade Dynamics, USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Mar. 31, 2014
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets	$ 0	$ 3,690
Quoted Prices in Active Markets (Level 1)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets	0	0
Significant Other Observable Inputs (Level 2)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets	0	0
Significant Unobservable Inputs (Level 3)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets	$ 0	$ 3,690