Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2019	Mar. 31, 2018
Trade and other receivables, allowance for doubtful accounts (in dollars)	$ 3,646	$ 4,032
Inventories, unliquidated progress payments (in dollars)	$ 0	$ 387,146
Common stock, par value (in dollars per share)	$ 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	49,887,268	49,669,848
Treasury stock, shares outstanding	2,573,652	2,791,072