Consolidated Balance Sheet Parenthetical (Parentheticals) - USD ($) $ in Thousands	Dec. 31, 2018	Mar. 31, 2018
Allowance for doubtful accounts	$ 5,836	$ 4,032
Unliquidated progress payments	$ 0	$ 387,146
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	52,460,920	52,460,920
Common stock, shares outstanding	49,848,073	49,669,848
Treasury Stock, Shares	2,612,847	2,791,072

A valuation allowance for trade and other receivables due to an Entity within one year (or the normal operating cycle, whichever is longer) that are expected to be uncollectible.

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