Income Taxes - Deferred Tax Assets and Deferred Tax Liabilities (Details) - USD ($) $ in Thousands	Dec. 30, 2017	Dec. 31, 2016
Deferred tax assets [Abstract]
Inventories	$ 10,598	$ 15,483
Other postretirement benefits and accrued items	9,239	13,180
Other reserves	9,029	9,821
Federal and foreign tax attributes	11,936	5,813
State tax attributes, net of federal benefit	29,720	22,572
Stock-based compensation	2,102	2,416
Basis difference in unconsolidated affiliates	0	211
Total deferred tax assets	72,624	69,496
Less valuation allowance	(30,316)	(18,681)
Deferred tax assets, net of valuation allowance	42,308	50,815
Deferred tax liabilities:
Property, plant, and equipment	43,972	52,319
Pension	3,841	4,633
Basis difference in unconsolidated affiliates	203	0
Total deferred tax liabilities	48,016	56,952
Net deferred tax liabilities	$ (5,708)	$ (6,137)