Organization and Summary of Significant Accounting Policies - Additional Information 1 (Details) - USD ($)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Schedule Of Organization And Presentation Of Financial Statements [Line Items]
Significant financial instruments with off-balance sheet risk	$ 0		$ 0
Interest and penalties recognized in condensed consolidated statements of income			0
Accrued interest or penalties related to uncertain tax positions	0		$ 0
Effective income tax rate			17.90%	24.50%
Reserve for reduction in account receivable			$ 1,069,000		$ 1,184,000
Trade promotions to customers	$ 428,000	$ 718,000	$ 2,212,000	$ 1,990,000
Minimum
Schedule Of Organization And Presentation Of Financial Statements [Line Items]
Useful life of property, plant and equipment			3 years
Useful lives of intangible assets			5 years
Maximum
Schedule Of Organization And Presentation Of Financial Statements [Line Items]
Useful life of property, plant and equipment			20 years
Useful lives of intangible assets			15 years
Production Equipment | Minimum
Schedule Of Organization And Presentation Of Financial Statements [Line Items]
Useful life of property, plant and equipment			15 years
Production Equipment | Maximum
Schedule Of Organization And Presentation Of Financial Statements [Line Items]
Useful life of property, plant and equipment			20 years
Production Support Equipment | Minimum
Schedule Of Organization And Presentation Of Financial Statements [Line Items]
Useful life of property, plant and equipment			3 years
Production Support Equipment | Maximum
Schedule Of Organization And Presentation Of Financial Statements [Line Items]
Useful life of property, plant and equipment			10 years
Office Furniture and Equipment | Minimum
Schedule Of Organization And Presentation Of Financial Statements [Line Items]
Useful life of property, plant and equipment			10 years
Office Furniture and Equipment | Maximum
Schedule Of Organization And Presentation Of Financial Statements [Line Items]
Useful life of property, plant and equipment			20 years
Office Equipment | Minimum
Schedule Of Organization And Presentation Of Financial Statements [Line Items]
Useful life of property, plant and equipment			3 years
Office Equipment | Maximum
Schedule Of Organization And Presentation Of Financial Statements [Line Items]
Useful life of property, plant and equipment			5 years