CONDENSED CONSOLIDATED STATEMENTS OF EARNINGS - USD ($)	3 Months Ended		9 Months Ended
	Dec. 31, 2016	Dec. 26, 2015	Dec. 31, 2016	Dec. 26, 2015
Income Statement [Abstract]
Net Sales	$ 369,705,000	$ 432,198,000	$ 979,566,000	$ 971,658,000
Costs and Expenses:
Cost of Product Sold	332,230,000	378,816,000	891,904,000	868,304,000
Selling and Administrative	21,116,000	19,505,000	57,023,000	51,955,000
Plant Restructuring	1,316,000	9,624,000	2,778,000	9,558,000
Other Operating (Income) Loss	1,153,000	(24,197,000)	1,172,000	(24,600,000)
Total Costs and Expenses	355,815,000	383,748,000	952,877,000	905,217,000
Operating Income (Loss)	13,890,000	48,450,000	26,689,000	66,441,000
Interest Expense, Net	2,414,000	2,191,000	6,709,000	5,772,000
Earnings From Equity Investment	(333,000)	46,000	(500,000)	132,000
Earnings (Loss) Before Income Taxes	11,809,000	46,213,000	20,480,000	60,537,000
Income Taxes Expense (Benefit)	3,628,000	15,090,000	6,217,000	19,924,000
Net Earnings (Loss)	8,181,000	31,123,000	14,263,000	40,613,000
Earnings (Loss) Attributable to Common Stock	$ 8,100,000	$ 30,832,000	$ 14,115,000	$ 40,180,000
Basic Earnings (Loss) per Common Share	$ 0.83	$ 3.12	$ 1.44	$ 4.06
Diluted Earnings (Loss) per Common Share	$ 0.82	$ 3.1	$ 1.43	$ 4.04