Significant Accounting Policies - Additional Information (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2015 USD ($) Customer	Sep. 30, 2014 USD ($)	Sep. 30, 2015 USD ($) Customer	Sep. 30, 2014 USD ($)	Dec. 31, 2014 USD ($)
Significant Accounting Policies [Line Items]
Subordinated note outstanding	$ 2,500,000		$ 2,500,000		$ 2,500,000
Maximum life of current operating leases			expire at various dates through 2024
Capital leases	6,000,000		$ 6,000,000		4,800,000
Accumulated amortization of capital leases	4,300,000		4,300,000		$ 4,000,000
Depreciation and amortization	4,081,000	$ 2,881,000	10,645,000	$ 8,649,000
Payments for interest	400,000	200,000	600,000	500,000
Income taxes	100,000	23,000	700,000	400,000
Assets Held Under Capital Leases
Significant Accounting Policies [Line Items]
Depreciation and amortization	$ 700,000	$ 700,000	$ 1,700,000	$ 1,900,000
Sales Revenue, Services, Net
Significant Accounting Policies [Line Items]
Number of customers representing more than 10% | Customer	1		1
Accounts Receivable
Significant Accounting Policies [Line Items]
Number of customers representing more than 10% | Customer	0		0
Credit Concentration Risk | Sales Revenue, Services, Net
Significant Accounting Policies [Line Items]
Concentration risk percentage			13.00%
Maximum
Significant Accounting Policies [Line Items]
Debt instrument covenant subordinated debt limit	$ 5,000,000		$ 5,000,000
Minimum
Significant Accounting Policies [Line Items]
Subordinated note outstanding	$ 2,500,000		$ 2,500,000