Note H - Revenue - Disaggregation of Revenue (Details) - USD ($)	3 Months Ended		6 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Net sales	$ 53,432,029	$ 26,077,710	$ 101,625,347	$ 49,160,979
Coil [Member]
Net sales	34,828,444	20,127,839	65,957,644	38,137,674
Coil [Member] | Prime Coil [Member]
Net sales	29,575,814	15,459,712	54,351,845	29,735,302
Coil [Member] | Secondary Coil [Member]
Net sales	4,894,421	4,442,760	11,004,879	7,811,364
Coil [Member] | Customer Owned [Member]
Net sales	358,209	225,367	600,920	591,008
Tubular [Member]
Net sales	18,603,585	5,949,871	35,667,703	11,023,305
Tubular [Member] | Manufactured Pipe [Member]
Net sales	14,214,209	2,989,288	25,169,596	6,322,722
Tubular [Member] | Mill Reject Pipe [Member]
Net sales	4,306,980	1,814,391	9,727,841	3,036,327
Tubular [Member] | Pipe Finishing Services [Member]
Net sales	$ 82,396	$ 1,146,192	$ 770,266	$ 1,664,256