Supplemental Consolidated Balance Sheet Information - Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Accrued Liabilities and Other Liabilities [Abstract]
Accrued vacation	$ 3,448	$ 2,949
Accrued commissions	1,730	1,649
Accrued bonuses	4,626	6,336
Estimated health insurance claims	745	800
Accrued other liabilities	3,281	5,031
Accrued expenses and other current liabilities	$ 13,830	$ 16,765