Summary of Significant Accounting Policies - Fair Value (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Assets:
Other long-term assets	$ 7,270	$ 5,064
Total Assets	7,270	5,064
Liabilities:
Interest rate swaps	6,736	2,031
Long term debt	247,630	269,739
Total Liabilities	256,383	274,322
Reconciliation of liability related to earnout
Balance at the beginning of the period	2,200	3,100
Adjustments to fair value		(900)
Balance at the end of the period		2,200	$ 3,100
Related Party Transactions
Related Party Transaction, Purchases from Related Party	0	0	0
Advertising expenses
Advertising expenses incurred	4,895	5,213	4,471
Research and development expenses
Research and development expenses	5,693	3,194	2,926
Henderson
Liabilities:
Earnout	17	352
Dejana
Liabilities:
Earnout	2,000	2,200
Level 3 | Henderson
Liabilities:
Earnout, portion in other current liabilities	17	352
Level 3 | Dejana
Liabilities:
Earnout, portion in other long term liabilities	2,000	2,200
Recurring | Level 2
Reconciliation of liability related to earnout
Derivative Liability, Current	1,522	127
Derivative Asset, Noncurrent	5,214
Derivative Liability, Noncurrent		1,904
Recurring | Level 3 | Henderson
Reconciliation of liability related to earnout
Balance at the beginning of the period	352	529
Adjustments to fair value	(217)
Payments to former owners	(118)	(177)
Balance at the end of the period	17	352	$ 529
Recurring | Level 3 | Dejana
Reconciliation of liability related to earnout
Balance at the beginning of the period	2,200
Adjustments to fair value	(200)
Balance at the end of the period	$ 2,000	$ 2,200