Debt Intruments (narrative) (detail) - USD ($)	3 Months Ended		9 Months Ended		12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015	Dec. 31, 2016	Dec. 26, 2015	Dec. 31, 2016	Dec. 09, 2016
Debt Instruments [Abstract]
Line of Credit Facility, Amount Outstanding	$ 232,586,000	$ 309,211,000	$ 232,586,000	$ 309,211,000	$ 232,586,000
Line of Credit Facility [Line Items]
Repayment of Notes Payable			22,596,000
Inventory Change	25,187,000		25,187,000		25,187,000
Defined Benefit Plan, Contributions by Employer			8,000,000	23,100,000
Relationship Transfer Agreement		24,275,000		24,275,000
Purchase Price	15,011,000		15,011,000		15,011,000
Net Earnings (Loss)	8,181,000	$ 31,123,000	14,263,000	$ 40,613,000	28,108,000
Accounts Receivable Change	7,624,000		7,624,000		7,624,000
Loan Agreement						$ 100,000,000
Production Period [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Current Borrowing Capacity	500,000,000		500,000,000		500,000,000
Nonproduction Period [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Current Borrowing Capacity	$ 400,000,000		$ 400,000,000		$ 400,000,000