Summary of Significant Accounting Policies - Fair Value (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Jul. 15, 2016
Assets:
Other assets	$ 3,458,000	$ 2,500,000
Total Assets	3,458,000	2,500,000
Liabilities:
Long term debt	315,940,000	185,540,000
Interest rate swaps	1,985,000	1,501,000
Total Liabilities	328,934,000	189,408,000
Advertising expenses
Advertising expenses incurred	4,269,000	4,511,000	$ 4,393,000
Henderson
Liabilities:
Earnout	636,000	761,000
Trynex
Liabilities:
Earnout		1,606,000
Dejana
Liabilities:
Earnout	10,373,000			$ 10,200,000
Level 3 | Henderson
Liabilities:
Earnout, portion in other current liabilities	194,000	319,000
Earnout, portion in other long term liabilities	442,000	442,000
Level 3 | Dejana
Liabilities:
Earnout, portion in other current liabilities	5,487,000
Earnout, portion in other long term liabilities	4,886,000
Recurring | Level 2
Reconciliation of liability related to earnout
Derivative Liability, Current	335,000	286,000
Derivative Asset, Noncurrent	1,650,000
Derivative Liability, Noncurrent		1,215,000
Recurring | Level 3 | Henderson
Reconciliation of liability related to earnout
Balance at the beginning of the period	761,000	600,000
Adjustments to fair value		322,000
Payments to former owners	(125,000)	(161,000)
Balance at the end of the period	636,000	761,000	600,000
Recurring | Level 3 | Trynex
Liabilities:
Earnout, portion in other current liabilities	1,606,000
Reconciliation of liability related to earnout
Balance at the beginning of the period	1,606,000	1,987,000
Adjustments to fair value		(113,000)
Payments to former owners	(1,606,000)	(268,000)
Balance at the end of the period		$ 1,606,000	$ 1,987,000
Recurring | Level 3 | Dejana
Reconciliation of liability related to earnout
Additions	10,200,000
Adjustments to fair value	173,000
Balance at the end of the period	10,373,000
Fleet Pride Inc,
Related Party Transactions
Related Party Transaction, Purchases from Related Party	$ 242,000