Nature of Operations and Summary of Significant Accounting Policies (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Jan. 01, 2019
Accounting Policies [Line Items]
Interest costs charged to expense	$ 338	$ 334	$ 289	$ 207	$ 250	$ 224	$ 379	$ 331	$ 1,168	$ 1,184	$ 1,294
Plus: Interest cost capitalized									562	293	198
Total									1,730	1,477	$ 1,492
Debt instrument, fair value disclosure	32,018				24,838				32,018	24,838
Long-term debt, including current maturities	$ 32,014				$ 24,554				$ 32,014	$ 24,554
ASU 2016-02 | Forecast
Accounting Policies [Line Items]
Right of use asset												$ 7,000
Operating lease liability												$ 7,000,000
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