Summary of Significant Accounting Policies - Fair Value (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Liabilities:
Long term debt	$ 186,529		$ 185,540
Interest rate swaps	3,381		1,501
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at the beginning of the period		$ 600
Adjustments to fair value		96
Payments to former owners		(61)
Balance at the end of the period		635
Derivative Liability, Current	379	88
Derivative Liability, Noncurrent	3,002	1,205
Henderson
Liabilities:
Earnout	709		761
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Derivative Liability, Current		193
Derivative Liability, Noncurrent		442
Trynex
Liabilities:
Earnout			1,606
Level 2
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Derivative Liability, Current	379		286
Derivative Liability, Noncurrent	3,002		1,215
Level 3 | Henderson
Liabilities:
Earnout, portion in other current liabilities	267
Earnout, portion in other long term liabilities	442
Recurring
Assets:
Other assets	3,264		2,500
Total Assets	3,264		2,500
Liabilities:
Total Liabilities	190,619		$ 189,408
Recurring | Level 3 | Henderson
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at the beginning of the period	761
Payments to former owners	(52)
Balance at the end of the period	709
Recurring | Level 3 | Trynex
Liabilities:
Earnout, portion in other current liabilities	0	2,032
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at the beginning of the period	1,606	1,987
Adjustments to fair value		313
Payments to former owners	$ (1,606)	(268)
Balance at the end of the period		$ 2,032