SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Description
Balance at beginning of year	$ 5,712	$ 5,190	$ 4,201
Additions charged to expense	11,251	9,783	10,247
Deductions	10,029	9,261	9,258
Balance at End of Year	6,934	5,712	5,190
Reserve for bad debts
Description
Balance at beginning of year	1,128	1,197	1,225
Additions charged to expense	676	38	27
Deductions	467	107	55
Balance at End of Year	1,337	1,128	1,197
Reserve for cash discounts
Description
Balance at beginning of year	692	724	659
Additions charged to expense	9,482	9,122	9,268
Deductions	9,562	9,154	9,203
Balance at End of Year	612	692	724
Deferred tax asset valuation
Description
Balance at beginning of year	3,892	3,269	2,317
Additions charged to expense	1,093	623	952
Balance at End of Year	$ 4,985	$ 3,892	$ 3,269