Nature of Operations and Summary of Significant Accounting Policies (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Jan. 01, 2019
Accounting Policies [Line Items]
Interest costs charged to expense	$ 368	$ 364	$ 321	$ 252	$ 338	$ 334	$ 289	$ 207	$ 1,305	$ 1,168	$ 1,184
Plus: Interest cost capitalized									575	562	293
Total									1,880	1,730	$ 1,477
Debt instrument, fair value disclosure	42,534				32,018				42,534	32,018
Long-term debt, including current maturities	41,060				32,014				41,060	32,014
Operating lease right-of-use assets, net	6,490				$ 0				6,490	$ 0
Total operating lease liability	$ 6,511								$ 6,511
ASU 2016-02
Accounting Policies [Line Items]
Operating lease right-of-use assets, net												$ 6,598
Total operating lease liability												$ 6,952
Minimum | Commodity Contract
Accounting Policies [Line Items]
Length of time hedged in commodity hedge									1 month
Maximum | Commodity Contract
Accounting Policies [Line Items]
Length of time hedged in commodity hedge									24 months
Building and improvements | Minimum
Accounting Policies [Line Items]
Estimated useful lives									10 years
Building and improvements | Maximum
Accounting Policies [Line Items]
Estimated useful lives									30 years
Machinery and equipment | Minimum
Accounting Policies [Line Items]
Estimated useful lives									3 years
Machinery and equipment | Maximum
Accounting Policies [Line Items]
Estimated useful lives									10 years
Office furniture and equipment | Minimum
Accounting Policies [Line Items]
Estimated useful lives									5 years
Office furniture and equipment | Maximum
Accounting Policies [Line Items]
Estimated useful lives									10 years
Computer equipment and software | Minimum
Accounting Policies [Line Items]
Estimated useful lives									3 years
Computer equipment and software | Maximum
Accounting Policies [Line Items]
Estimated useful lives									5 years
Motor vehicles
Accounting Policies [Line Items]
Estimated useful lives									5 years